The Effect of Low-Skilled Immigration on U.S. Prices: Evidence from CPI Data Patricia Cortes University of Chicago I exploit the large variation across U.S. cities and through time in the relative size of the low-skilled immigrant population to estimate the causal effect of immigration on prices of nontraded goods and services. Using an instrumental variables strategy, I find that, at current immigration levels, a 10 percent increase in the share of low-skilled immigrants in the labor force decreases the price of immigrantintensive services, such as housekeeping and gardening, by 2 percent. Wage equations suggest that lower wages are a likely channel through which these effects take place. However, wage effects are significantly larger for low-skilled immigrants than for low-skilled natives, implying that the two are imperfect substitutes. I. Introduction Most research to date on the impact of low-skilled immigration on the U.S. economy has focused on native wage levels. The net effect of immigration on natives’ purchasing power, however, depends not only on wage but also on price effects. If immigration bids down the price of I am very grateful to Joshua Angrist, David Autor, and Esther Duflo for their support and valuable comments. Suggestions from an anonymous referee, a second editor, and Steven Levitt (the editor) substantially improved the paper. I thank Daron Acemoglu, Abhijit Banerjee, Marianne Bertrand, Jose Tessada, and participants in the field lunches at Massachusetts Institute of Technology and in seminars at University College London, University of California at Los Angeles, San Diego, and Irvine, Chicago Graduate School of Business, Stanford Graduate School of Business, and Northwestern for helpful comments. I also thank the Consumer Price Index unit of the Bureau of Labor Statistics, in particular William Cook, for generous assistance with the data. This work is supported by the William Ladany Faculty Research Fund at the Graduate School of Business, the University of Chicago. [ Journal of Political Economy, 2008, vol. 116, no. 3] 䉷 2008 by The University of Chicago. All rights reserved. 0022-3808/2008/11603-0004$10.00 381 382 journal of political economy low-skilled labor, this will reduce the price of unskilled-intensive goods and services, thereby raising the welfare of consumers of these goods. This paper uses confidential micro data from the consumer price index (CPI) and exploits the large variation across cities and through time in the relative size of the low-skilled immigrant population to estimate the causal effect of immigration on prices of nontraded goods and services. The empirical strategy presents two main challenges. First, immigrants do not choose their locations randomly. Unobserved economic factors that attract immigrants to a city are likely to also affect prices, thereby biasing the estimation. Second, the effect of immigration on prices of nontraded goods will depend not only on the relative immigrant labor intensity of the nontraded good’s technology but also on the degree to which natives respond to immigration to a local market by moving their labor or capital to other cities. Displacement effects will disperse the price effect across cities, and the empirical exercise will provide only a lower bound for the full magnitude of the effects. To ameliorate the bias that arises from endogenous location choices of immigrants, I use the historical distribution of immigrants from countries for which data are available in 1970 as an instrument for the recent distribution of the immigrant population. The instrument is based on the notion that immigrant networks are an important consideration in the location choices of prospective immigrants and that the determinants of the historical distribution of immigrants are likely to be uncorrelated with recent changes in the relative economic performance of cities in the same geographic region. As initial evidence of the impact of low-skilled immigration, I present reduced-form price equations for nontraded services that use intensively low-skilled immigrant labor. The explanatory variable of interest is the share of low-skilled workers in the labor force. The instrumental variable estimates imply that at current immigration levels, a 10 percent increase in the share of low-skilled immigrants in the labor force of a city reduces prices of immigrant-intensive services, such as gardening, housekeeping, babysitting, and dry cleaning, by approximately 2 percent. The magnitude of the effect suggests that the immigration wave of the 1980– 2000 period decreased the prices of immigrant-intensive services by at least a city average of 9–11 percent. I estimate a similar specification for the prices of nontraded services that use low-skilled immigrant labor moderately and for services that use it very little. I find that the coefficient for the former is negative but significantly smaller in magnitude than for immigrant-intensive services, and zero for the latter. An alternative specification is to interact the share of low-skilled workers in a city with a measure of how low-skilled immigrant labor intensive a nontraded good or service is. Using Census data, I construct the share low-skilled immigration and u.s. prices 383 of total workers in the industry who were foreign-born high school dropouts. The direct effect of low-skilled immigrants on the prices of nontraded goods is close to zero and not statistically significant. The interaction term with the technology variable is highly negative and statistically significant. The focus on local conditions limits the set of goods and services whose prices can be analyzed to those considered nontradable at the city level. Consistent with the hypothesis that U.S. cities could be considered small open economies, I find that the local concentration of low-skilled immigrants has little impact on the prices of traded goods. This is true in all the specifications. I next turn to explore the channels through which the price effects are likely to take place. Given the nature of the services in which immigrants work, the obvious channel through which the prices go down after a low-skilled immigration shock is a reduction in wages. Most crosscity studies (including the present), however, have failed to find sizable effects on low-skilled native wages. A simple trade model that allows lowskilled immigrants and low-skilled natives to be imperfect substitutes provides a solution to the puzzle of the joint finding of sizable price effects and no native wage effects. If natives and immigrants are imperfect substitutes, a low-skilled immigration shock should affect mostly the wages of other low-skilled immigrants and have a smaller effect on the wages of typical low-skilled natives. Immigrant wage regressions show significant negative effects for female immigrants but fail to find a similar result for immigrant males. Simple tabulations of Census data, combined with inconclusive results from previous studies, suggest that wage data for low-skilled immigrants might be noisy. To indirectly tackle this issue, I show that low-skilled immigration has had a large negative effect on the wages of the low-skilled natives who are most likely to compete directly with immigrants in the labor market, those of Hispanic origin, and those with low English proficiency. The magnitude of the wage effects for these groups is comparable to the magnitude of the price effects. No native wage effects at the city level do not imply that immigrants have no impact on natives’ labor opportunities. If displacement effects are sizable for natives, the cross-city comparison will not capture the full impact on natives’ wages. Following Borjas (2006), I estimate wage regressions in which the labor market is defined at the state level. I find larger and now statistically significant effects of an immigrant influx on the wages of low-skilled natives, suggesting that there is some native migration response to immigration shocks at the city level. Note, however, that the presence of displacement effects does not imply that immigrants and natives are perfect substitutes. If they were, wage effects 384 journal of political economy estimated at the city level would have to be of a similar magnitude for natives and immigrants. Section V of the paper uses data on consumption patterns from the Consumer Expenditure Survey (CEX) to assess which groups of the native population benefit the most from a decline in the prices of immigrant-intensive services and by how much this decline reduces the cost of their consumption basket. I find that price effects resulting from the immigration wave of the past two decades were larger for highskilled natives, especially for those with a graduate degree (⫺0.4 percent), rather than for low-skilled natives (⫺0.3 percent), because they devote a larger share of their budget to immigrant-intensive services. However, even for very high-skilled natives, the effect is small: expenditure shares of immigrant-intensive services are never higher (on average) than 4.3 percent of the total budget. Very few papers have looked at immigration’s impact on the prices of goods and services. A recent exception is the paper by Lach (2007), who studies how an unexpected arrival of a large number of immigrants from the former Soviet Union to Israel affected the prices of goods and services. Exploiting cross-city variation in the concentration on immigrants, he finds that a one-percentage-point increase in the ratio of immigrants to natives decreased prices by 0.5 percentage point. He argues that the higher elasticity of demand of immigrants and their lower search costs gave incentives to retailers to lower their prices to attract the new customers. His proposed mechanism is unlikely to explain the results obtained here for several reasons. First, immigrants consume very little of household-related services. Second, U.S. lowskilled immigrants, unlike the immigrants who arrived in Israel, have very high labor force participation rates and therefore do not have particularly low search costs compared with natives. Finally, Lach’s estimates are for the short run; as he mentions, the effects are likely to decline in the long run as immigrants become assimilated.1 However, a vast literature has looked at the wage effects of immigration. My estimates of the local impact of low-skilled immigration on natives’ wages are in line with what most other cross-city studies have found (see Card 1990, 2005; Altonji and Card 1991; LaLonde and Topel 1991; Card and Lewis 2007): the effect of immigration on the labor market outcomes of natives is small. A few hypotheses have been proposed to explain this finding. Borjas, Freeman, and Katz (1996) and Borjas (2003, 2006) argue that if labor and capital adjust to immigration by moving across cities, then the relevant unit of analysis is the entire 1 Khananusapkul (2004) is also related to the present study. The author’s finding that an increase in the proportion of low-skilled female immigrants in a metropolitan area raises the proportion of private household workers and lowers their wages supports the hypothesis presented here. low-skilled immigration and u.s. prices 385 country, and cross-city comparisons will fail to find significant effects. Lewis (2005), however, claims that local economies are the relevant unit of observation, but that the technologies of local firms—rather than the wages that they offer—respond to changes in local skill mix associated with immigration. The hypothesis that cities adapt to immigration by shifting industry composition is rejected by Card and Lewis (2007). My estimations provide evidence for Borjas’s hypothesis, but they also imply that displacement effects cannot be the only explanation; exploiting cross-city variation, I find large negative wage effects for immigrants and native Hispanics. These results point to a complementary reason: low-skilled natives and low-skilled immigrants are far from being perfect substitutes. Therefore, a low-skilled immigration shock should affect mostly the wages of other low-skilled immigrants and have a smaller effect on the wages of low-skilled natives.2 The rest of the paper is organized as follows. In Section II, I describe the data and descriptive statistics and discuss industry variation in the use of low-skilled immigrant labor. A simple theoretical framework is presented in Section III. Empirical results are reported and discussed in Section IV. Purchasing power calculations are reported in Section V, and Section VI presents conclusions. II. Data A. Immigration Data This paper uses the 1980, 1990, and 2000 Public Use Microdata Samples (PUMS) of the Decennial Census to measure the concentration of lowskilled immigrants among cities. Low-skilled workers are defined as those who have not completed high school. An immigrant is defined as someone who reports being a naturalized citizen or not being a citizen. The analysis is restricted to people aged 16–64 who report being in the labor force. Table 1 shows the evolution of the share of low-skilled immigrants in the labor force for the 30 largest cities in the United States. Two facts should be emphasized. First, there is substantial variation across cities in the concentration of low-skilled immigrants. Immigrants are heavily concentrated in large cities, such as Los Angeles, New York, and Miami. In Los Angeles, for example, one of six workers is a high school dropout immigrant. In other smaller cities, low-skilled immigrants are a negligible share of the labor force. In Cincinnati, for example, in 2000 there were fewer than five low-skilled immigrant workers per 1,000 participants in the labor force. Second, during the 1990s, new waves of low-skilled 2 Most of the literature to date has assumed perfect substitutability between immigrants and natives. A recent exception is Ottaviano and Peri (2006). 386 journal of political economy TABLE 1 Share of Low-Skilled Immigrants in the Labor Force (%) City 1980 1990 2000 Atlanta Baltimore Boston Buffalo Chicago Cincinnati Cleveland Columbus Dallas–Fort Worth Denver-Boulder Detroit Honolulu Houston Kansas City Los Angeles Miami Milwaukee Minneapolis New Orleans New York Philadelphia Phoenix Pittsburgh Portland St. Louis San Diego San Francisco Seattle Tampa Washington, DC .38 .76 3.53 1.48 4.99 .44 1.82 .43 2.13 1.18 1.76 4.71 3.96 .58 11.64 15.13 1.07 .49 1.20 8.91 1.39 2.19 .57 1.03 .49 4.59 4.40 1.22 1.50 1.61 .84 .44 2.71 .72 5.09 .23 .89 .25 5.17 1.42 .93 3.66 7.03 .47 15.90 14.44 .84 .37 1.13 7.82 .91 3.30 .27 1.53 .24 5.92 6.73 1.00 1.69 2.52 3.23 .67 2.62 .47 5.86 .34 .65 .81 8.63 4.13 1.35 3.18 9.21 1.44 15.09 11.36 1.54 1.43 1.08 8.15 1.06 6.41 .21 3.27 .53 6.34 6.19 1.94 2.15 3.76 Source.—U.S. Census. immigrants chose to locate to new cities. So, despite the large flows of new immigrants to the country, Los Angeles, New York, and Miami did not see an increase in the share of high school dropout immigrants in their labor forces. Cities such as Denver, Dallas, Washington, DC, and especially Atlanta, however, experienced a significant increase in the concentration of low-skilled immigrants. B. Price Data Under a confidentiality agreement with the Bureau of Labor Statistics (BLS), I was granted access to the CPI Research Database (RDB). This data set contains the store-level data used to construct the CPI. It also includes estimates of price indexes at lower levels of geography and product classification that are not available to the public. The RDB covers the years 1986–2002. To increase the number of observations, I low-skilled immigration and u.s. prices 387 (linearly) interpolate the immigration variables for 1986, so that I have price data for 30 cities and three time periods for each good.3 The paper uses price indexes at the city-industry level. The analysis is restricted to A-sized cities as defined by the BLS (metropolitan areas with 1980 populations greater than 1.2 million), where sufficient quotes are collected to produce reliable indexes.4 The number of goods and services included in the CPI that can be used in the present analysis is restricted by the ability to match them to the industry classification of the census. The paper uses the Census data to construct a measure of the industry’s low-skilled labor factor share. The matching process results in a sample of 74 goods and services, 34 of which are nontradable (see App. table A1 for a list of goods and services).5 C. Industries Intensive in Low-Skilled Immigrant Labor There is much between-industry variation in the use of low-skilled immigrant labor. Apparel is a good example of a low-skilled-immigrantintensive industry: 38 percent of all workers in the industry are lowskilled immigrants, close to eight times the percentage in the overall labor force. However, there are industries with virtually no low-skilled immigrants: in the accounting services industry, for example, fewer than one of every 1,000 employees is a foreign-born high school dropout. Table 2 shows the industries with the highest share of low-skilled immigrants, low-skilled female immigrants, and low-skilled male immigrants in the year 2000. With the exception of agriculture and apparel/ textiles, almost all other industries fall into the category of nontraded services: landscaping, housekeeping, laundry and dry cleaning, car washes, shoe repair, and services for buildings and dwellings. Once other inputs are taken into account, it is very likely that some of these services are significantly more immigrant labor intensive than the top traded industries in table 2.6 The low-skilled immigrant concentration in these nontraded services is very large. For example, whereas low-skilled im3 All the results are robust to restricting the empirical analysis to price changes between 1990 and 2000 or to using 1980 immigration variables for 1986 prices. See App. table C1. 4 A revision to the CPI in 1998 changed some of the geographic area samples and incorporated a new item structure. Buffalo and New Orleans, A-sized units before the revision, were excluded from this group after the revision, and Washington, DC, and Baltimore were merged into a single unit. For these cities, in an effort to maximize the number of observations, the present analysis assigns the index value of December 1997 to January 2000. A similar strategy was followed for items that did not have a perfect match in the new structure. 5 Because of confidentiality restrictions, I cannot present detailed statistics of the price data used in this paper. 6 Data from the 2002 Economic Census show that payroll is half the costs of materials and capital expenditures for the textile products industry and double for the apparel industry. TABLE 2 Top Industries Intensive in Low-Skilled Immigrant Labor Immigrants (%) Natives (%) A. All Low-Skilled Workers Labor force Apparel/textile industry Landscaping services Private households Crop production Animal slaughtering Fruit and vegetable preservation Car washes Services to buildings Shoe repair Furniture and fixtures Dry cleaning and laundry services Sugar products 5.2 37.8 29.7 27.0 25.3 24.7 20.1 19.9 19.6 19.6 19.4 19.2 19.2 6.4 7.7 10.8 9.3 12.9 12.2 8.7 23.2 11.9 10.6 8.4 12.6 9.8 B. Male Low-Skilled Workers Labor force Landscaping services Crop production Shoe repair Car washes Apparel/textile industry Animal slaughtering Furniture and fixtures Recyclable material Bakeries, except retail Construction Taxi and limo service Coating, engraving activities 3.3 28.9 20.0 19.6 17.4 16.4 16.0 15.4 13.5 12.0 11.9 10.6 10.4 3.6 9.9 10.1 9.5 20.1 1.4 8.1 6.5 11.8 5.8 8.8 4.0 9.6 C. Female Low-Skilled Workers Labor force Apparel/textile industry Private households Fruit and vegetable preservation Dry cleaning and laundry services Sugar products Services to buildings Animal slaughtering Traveler accommodation Pottery, ceramics Nail salons Bakeries, except retail Seafood products 1.9 28.7 25.4 12.4 12.2 11.3 11.3 8.7 8.0 7.7 7.1 6.4 6.3 2.8 2.6 8.1 4.3 8.8 5.8 5.8 4.0 5.4 2.2 5.1 3.9 2.3 Source.—2000 Census. Note.—Percentage represents the share of low-skilled immigrants in total employment of the industry. The 30 largest U.S. cities are included. low-skilled immigration and u.s. prices 389 migrant women represented 1.9 percent of the total labor force in the year 2000, they represented more than 25 percent of the workers in private household occupations and 12 percent of the workers in laundry and dry cleaning services. Similarly, the immigrant men’s share in gardening was nine times larger, and their share in shoe repair six times larger, than their share in the total labor force. The concentration of low-skilled immigrants in these industries is not solely an outcome of their low education level; indeed, native high school dropouts are much less likely to work in these industries (see table 2). Gardening and housekeeping are good examples: whereas 60 percent of high school dropouts in the labor force in 2000 were natives, they make up only close to a quarter of the dropouts working in one of these two services. Immigrants’ low proficiency in English and, for some, their legal status might limit their job opportunities compared with low-skilled natives. III. Theoretical Background In this section I use a simple Heckscher-Ohlin framework to model the impact of immigration on the prices of nontraded goods. The presence of a nontraded sector in the model breaks the “factor price insensitivity” result of a two-traded-sectors model (Leamer 1995), and thus, wages of low-skilled workers will be determined locally. Wages are going to be the main mechanism through which the impact on prices occurs. A key feature of the model is that low-skilled immigrants and low-skilled natives need not be perfect substitutes. This is important because it will help reconcile the seemingly contradictory findings of negligible native wage effects and significant price effects of a low-skilled immigration influx. The many simplifying assumptions (the model abstracts from the possibility of low-skilled immigration affecting prices through changes in demand, wages of high-skilled workers, or returns to capital) require that when comparing the model’s predictions with the results of the empirical model, one has to be careful in interpreting the econometric estimates as informative structural parameters. Nevertheless, the model does provide a simple framework to test the economic plausibility of the empirical results and introduces some issues that will become relevant in the analysis of the results later on. A. Setup Consider a small open economy that produces two goods, one traded (T) and one nontraded (NT). There are three factors of production: high-skilled native labor (H), low-skilled native labor (L), and low-skilled immigrant labor (I ). The total supply of factors is represented by H, L, 390 journal of political economy and Ī , respectively. For simplicity, I assume that only high-skilled native labor participates in the production of the traded good: T p HT . (1) The nontraded good production function is a nested constant elasticity of substitution: a r NT p HNT [(LrNT ⫹ INT )1/r]1⫺a, (2) where 0 ! r ≤ 1 and 0 ! a ! 1. This specification implies that the elasticity of substitution between the low-skilled labor aggregate and highskilled labor is equal to one and that the elasticity of substitution between L and I is j p 1/(1 ⫺ r). This specification allows for perfect substitution between immigrant and native low-skilled labor (j p ⬁), for a CobbDouglas specification between the two factors (j p 1), and for perfect complementarity between them (j p 0). To keep the analysis simple, I have excluded capital from the production functions. Doing so is equivalent to keeping the supply of capital perfectly elastic, a reasonable assumption for local markets. The economy admits a representative consumer with a Cobb-Douglas type utility: U p T g(NT )1⫺g. (3) Note that the assumption of homotheticity of the utility function implies no income effects and that there is no role for differences in preferences between natives and immigrants. I assume that all markets are competitive. The economy takes as given the price of the tradable good PT , which is normalized to one. B. Equilibrium The maximization of utility leads consumers to spend a fraction g of their income in the consumption of the traded good and 1 ⫺ g in the consumption of the nontraded good. This condition plus market clearing in the nontraded market imply that the following equation holds: a HNT [(Lr ⫹ I¯ r)1/r]1⫺a p (1 ⫺ g)(wH H ⫹ wLL ⫹ wII¯ ) PNT , (4) where the left side of equation (4) represents the total supply of the nontraded good and the right side the total demand. Note that I have already incorporated the conditions L NT p L and INT p I¯ . Because all factors will be paid the value of their marginal product in competitive markets and because the marginal product of high-skilled low-skilled immigration and u.s. prices 391 workers should be equal in both sectors, the following equilibrium equations result: a wL p (1 ⫺ a)PNTHNT Lr⫺1(Lr ⫹ I¯ r)[(1⫺a)/r]⫺1, (5) a ¯ r⫺1 wI p (1 ⫺ a)PNTHNT I (Lr ⫹ I¯ r)[(1⫺a)/r]⫺1, (6) a⫺1 1 p aPNTHNT [(Lr ⫹ I¯ r)1/r]1⫺a, (7) and where the right sides of equations (5), (6), and (7) represent the value of the marginal product of low-skilled natives, low-skilled immigrants, and high-skilled workers, respectively. Equations (4)–(7) provide a system of four equations and four unknowns (PNT , HNT , wL , and wI). Solving the system, I obtain that the equilibrium relative price of nontraded goods is given by ⫺(1⫺a) (Lr ⫹ I¯ r)1/r (1 ⫺ g)1⫺a PNT p a # . a [a ⫹ g(1 ⫺ a)]1⫺a H [ ] (8) Equation (8) shows that the relative price of the nontraded good depends positively on the consumer’s preference for it, 1 ⫺ g, and negatively on the relative supply of low-skilled versus high-skilled labor. An increase in H will raise the relative production of the traded good (and therefore reduce its relative price), the more so the higher 1 ⫺ a is, that is, the less intensive the nontraded good is in high-skilled labor. The same logic explains why the relative price will decrease as low-skilled labor becomes more abundant. Equilibrium wages for low-skilled natives and low-skilled immigrants are given by ⫺1 ( ) Lr ⫹ I¯ r 1⫺g r⫺1 wL p (1 ⫺ a) #L # a ⫹ g(1 ⫺ a) H (9) and ⫺1 ( ) Lr ⫹ I¯ r 1⫺g wI p (1 ⫺ a) # I¯ r⫺1 # a ⫹ g(1 ⫺ a) H . (10) If immigrants and natives are perfect substitutes, then both groups will receive the same wage rate, which will depend negatively on the relative supply of low- versus high-skilled labor. 392 C. journal of political economy The Effect of an Immigration Shock To determine the effect of an immigration shock on prices, I begin by taking logs of equation (8): ln (PNT) p c ⫺ (1 ⫺ a) ln (Lr ⫹ I¯ r)1/r [ ] H , (11) where c p ln { } (1 ⫺ g)1⫺a . a [a ⫹ g(1 ⫺ a)]1⫺a a Differencing (11) with respect to low-skilled immigration, I obtain the elasticity of the relative price of the nontraded good to low-skilled immigration: ⭸ ln [(Lr ⫹ I¯ r)1/r/H ] ⭸ ln PNT p ⫺(1 ⫺ a) ! 0. ⭸ ln I¯ ⭸ ln I¯ (12) Equation (12) shows that the elasticity of the relative price of the nontraded good to a shock to low-skilled immigration depends on two factors: the low-skilled labor intensity of the nontraded good (1 ⫺ a) and immigration’s effect on the relative amount of aggregate low-skilled labor to high-skilled labor. This last effect can be decomposed as follows: ⭸ ln [(Lr ⫹ I¯ r)1/r/H ] Lr ⭸ lnL Ī r p # ⫹ . r r r ⭸ ln I¯ ⭸ ln I¯ L ⫹ I¯ r L ⫹ I¯ (13) If immigrants displace natives, ⭸L/⭸I¯ ! 0,7 the local price effects of immigration will be attenuated. If displacement effects are strong enough, one to one in the case of perfect substitution, price effects will disappear. However, if displacement effects are negligible, then ( ) ⭸ ln PNT I¯ r p ⫺(1 ⫺ a) ! 0, r ⭸ ln I¯ L ⫹ I¯ r (14) and the elasticity of prices with respect to a low-skilled immigration shock will be proportional to the initial share of immigrants in the lowskilled labor aggregate. The negative effect of an immigration shock on the relative price of 7 Note that, for simplicity, I have assumed that L and I are perfectly inelastic. Therefore, allowing ⭸L/⭸I¯ ( 0 refers to the possibility that natives move to another city, and not to people changing their labor supply decisions. low-skilled immigration and u.s. prices 393 the nontraded good will hold under more general constant-returns-toscale technologies if two conditions are satisfied: there are more factors than traded goods and the nontraded sector is more intensive in lowskilled immigrant labor than the traded sector. The magnitude of this effect will depend on the difference in skill intensities between the two sectors.8 As shown in equation (15) below, the effect of low-skilled immigration on the wages of low-skilled natives depends on two key factors: the elasticity of substitution between the two inputs and the degree to which immigrants displace natives: ⭸ lnL Lr ⭸ ln wL I¯ r p ⫺ 1 ⫺ r ⫹ r ⫺ r . ⭸ ln I¯ ⭸ ln I¯ Lr ⫹ I¯ r Lr ⫹ I¯ r ( ) (15) This equation makes clear that a very small response of wages of lowskilled natives to an influx of low-skilled immigrants can be the result of two very different forces. On the one hand, wages will not change significantly if natives leave the city or the labor force, an argument made by the critics of cross-city studies (Borjas 2003). On the other hand, even if ⭸ lnL/⭸ ln I¯ p 0, wages of natives will not react much if native labor and immigrant labor are not close substitutes (r r 0). A way to disentangle the two alternatives is to look at the wages of low-skilled immigrants: ⭸ lnL Lr ⭸ ln wI I¯ r p ⫺(1 ⫺ r) ⫺ r ⫺ r . r r r ⭸ ln I¯ ⭸ ln I¯ L ⫹ I¯ L ⫹ I¯ r (16) If the presence of displacement effects is the major explanation behind the low response of native wages, immigrant wages should not react much either. If imperfect substitution plays an important role, wages of low-skilled immigrants should decrease significantly after an immigration flow, even if displacement effects are nonzero. 8 Specifically, if the traded good’s production function is T p HTb[(LTr ⫹ ITr)1/r]1⫺b, it is easy to show that r ⭸ ln [(L ⫹ I¯ r)1/r/H] ⭸ ln PNT p (a ⫺ b) # . ⭸ ln I¯ ⭸ln I¯ 394 IV. journal of political economy Empirical Strategy and Estimations The paper exploits the large variation across cities and through time in the relative size of the low-skilled immigrant population to identify the impact of immigration on prices and wages. There are two major concerns with the validity of this identification strategy. The first one is that immigrants do not choose their location randomly, and thus location decisions might be correlated with unobserved determinants of prices and wages. Subsection A discusses the instrument I use to solve for the endogeneity of the distribution of immigrants. The second concern is that natives might respond to the influx of low-skilled immigrants to a city by changing their location decisions. As the model from the previous section shows, if there are displacement effects (⭸L/⭸I¯ ! 0), cross-city comparisons will not capture the full effects of low-skilled immigration on prices and wages. If displacement effects are not very large, however, estimates using variation at the city level will provide informative lower bounds on the full magnitude of the effects and will also help explain differences across cities in prices and in the wages of low-skilled natives and immigrants. Most of the papers that have empirically tested natives’ migration response to immigration have not found evidence of large displacement effects. Card and DiNardo (2000) and Card (2001, 2005), using different samples and specifications, have found that native mobility has virtually no offsetting effect on the relative supply shocks created by immigration. Evidence that immigrants do displace natives, but at low rates, is provided by Federman, Harrington, and Krynski (2006), who found that for every five Vietnamese manicurists who entered the market in California, two non-Vietnamese were displaced, and that the displacement appears to have been primarily due to a reduction in the number of non-Vietnamese entering the occupation rather than to an increase in the number of current manicurists leaving it. Saiz (2007) argues that his result that immigration has changed the local rents and house prices is consistent with the idea that immigrants do not displace natives, at least not one for one. Larger but still not perfectly offsetting displacement effects are found by Borjas (2006). He estimates that 6.1 fewer native workers choose to reside in a city for every 10 new immigrants that arrive to the city. After discussing the instrument, I will provide evidence that, even though natives do respond to the entry of immigrants to a city, displacement effects are not nearly large enough to equalize prices and wages across cities. low-skilled immigration and u.s. prices A. 395 Instrument The instrument exploits the tendency of immigrants to settle in a city with a large enclave of immigrants from the same country. Immigrant networks are an important consideration in the location choices of prospective immigrants because these networks facilitate the job search process and assimilation to the new culture (Munshi 2003). The instrument uses the 1970 distribution of immigrants from a given country across U.S. cities to allocate the new waves of immigrants from that country. For example, if a third of Mexican immigrants in 1970 were living in Los Angeles, the instrument allocates 33 percent of all Mexicans in the 1990s to Los Angeles. Formally, the instrument for the number of low-skilled immigrants in city i and decade t can be written as 冘 j Immigrantsji1970 # LS Immigrantsjt , Immigrantsj1970 (17) where j are all countries of origin included in the 1970 Census,9 Immigrantsji1970 /Immigrantsj1970 represents the percentage of all immigrants from country j included in the 1970 Census who were living in city i, and LS Immigrantsjt stands for the total number of low-skilled emigrants from country j to the United States in decade t. As can be seen in table 3, the instrument is a good predictor of low-skilled workers and immigrant shares.10 The magnitudes of the coefficients suggest that, at current U.S. immigration levels, an increase of 10 percent in the predicted number of low-skilled immigrants increases the share of lowskilled immigrants in the labor force between 6.2 percent and 8.1 percent and the share of low-skilled workers between 2.7 percent and 3.5 percent. Most of the econometric specifications in the paper include city and region#decade fixed effects. Therefore, the instrument will help in identifying the causal effect of immigration concentration on prices and wages as long as three conditions hold: 9 A list of the countries included in the construction of the instrument is presented in App. table B3. 10 Appendix table B1 presents the first-stage regressions that use the 1986 interpolated values instead of the 1980 Census data. The results are quantitatively and qualitatively very similar. I use a logarithmic functional form in table 3 because the price equation derived from the theoretical model (Sec. II) is expressed in logs. Appendix table B2 presents an alternative functional form for the first stage that will be used in Sec. IV.B and serves as a check on the robustness of the instrument. 冘 .797 (.173)*** No Yes .950 90 .623 (.198)*** Yes Yes .960 90 (2) .809 (.206)*** Yes No .958 81 (3) .350 (.061)*** No Yes .973 90 (4) .284 (.064)*** Yes Yes .976 90 (5) .270 (.065)*** Yes No .981 81 (6) Note.—OLS estimates. City and decade fixed effects are included in all the regressions. Robust standard errors are reported in parentheses. Regressions are weighted by the size of the labor force. Results from unweighted regressions are almost identical. * Significant at the 10 percent level. ** Significant at the 5 percent level. *** Significant at the 1 percent level. Region#decade fixed effects Includes California R2 Observations ln [ j (Immigrantsji 70/Immigrantsj 70 ) # LS Immigrationjt] (1) ln[(LS Immigrants ⫹ LS Natives)/ Labor Force] Dependent Variable ln(LS Immigrants/Labor Force) TABLE 3 First Stage low-skilled immigration and u.s. prices 397 1. The unobserved factors determining that more immigrants decided to locate in city i versus city i (both cities in the same region) in 1970 are not correlated with changes in the relative economic opportunities offered by the two cities in the following decades.11 The identification assumption is not violated, for example, by Sun Belt cities growing faster than cities in other regions (for several decades) and at the same time being important immigrant cities. 2. The total (national) flow of low-skilled immigrants in a given decade (second term in the interaction) is exogenous to differential shocks to cities within a given region. 3. The only channel through which immigrant distribution in 1970 affects recent changes in prices is its effect on the actual distribution of low-skilled immigrants across cities (exclusion restriction). B. Displacement Effects I follow Card (2005) and use the following specification to test for displacement effects: LS Nativesirt ⫹ LS Immigrantsit LS Immigrantsit pd ⫹ fi ⫹ wrt ⫹ ijt , Labor Forceit Labor Forceit (18) where i is city, r region, and t decade, and fi and wrt represent city and region#decade fixed effects, respectively. If there are no displacement effects, d p 1, an increase of one percentage point in the share of low-skilled immigrants should lead to an increase of the same magnitude in the share of low-skilled workers. If 11 A more formal discussion is presented here. Consider the following simplified version of the model: yirt p a ⫹ bIirt ⫹ prt ⫹ vi ⫹ eirt , where i represents a city, r a region, and t a decade; yirt is the dependent variable of interest (e.g., prices); Iirt is a variable related to low-skilled immigration; prt are region#decade fixed effects; and vi are city fixed effects. The equation above can be reexpressed as (yirt ⫺ yirt⫺1) ⫺ (yi rt ⫺ yi rt⫺1) p b[(Iirt ⫺ Iirt⫺1) ⫺ (Ii rt ⫺ Ii rt⫺1)] ⫹ [(irt ⫺ irt⫺1) ⫺ (i rt ⫺ i rt⫺1)], where i and i are located in the same region. If the instrument for Iirt is given by li,1970 # TIt (li,1970 is the share of immigrants who were in city i in 1970 and TIt the national flow of immigrants in year t), then the identification condition becomes (irt ⫺ irt⫺1) ⫺ (i rt ⫺ i rt⫺1) is uncorrelated with (li,1970 ⫺ li ,1970)(TIt ⫺ TIt⫺1). If, e.g., li,1970 ⫺ li ,1970 was influenced by a shock to the demand for low-skilled services in city i in 1970 and the shock was permanent, it will cancel out by first differentiating the error terms. 398 journal of political economy TABLE 4 Displacement Effects of Low-Skilled Immigration Dependent Variable: (LS Natives ⫹ LS Immigrants)/Labor Force OLS LS Immigrants/ Labor Force Region#decade fixed effects Includes California Observations IV (1) (2) (3) (4) (5) .992 (.197)*** .778 (.147)*** 1.274 (.279)*** .712 (.246)*** .796 (.280)*** No Yes No Yes Yes Yes 90 Yes 90 Yes 90 Yes 90 No 81 Note.—All regressions include city and decade fixed effects. Standard errors clustered at the city#decade level are reported in parentheses. The instrument is j (Immigrantsji1970/Immigrantsj1970 ) # LS Immigrantsjt and its square. See App. table B2 for the first stage. Regressions are weighted by the size of the labor force. Results from unweighted regressions are almost identical. * Significant at the 10 percent level. ** Significant at the 5 percent level. *** Significant at the 1 percent level. 冘 every immigrant that comes to city i triggers a low-skilled native to move to another city, then d p 0. Given that the unobserved factors that determine the location of immigrants are likely to influence also the location decisions of natives, I use instrumental variables to estimate equation (18). Table 4 presents the results. The magnitude of the estimated d (d̂ p 0.71) suggests that there is some displacement taking effect but that it is far from one to one: for every 10 immigrants that arrive to a city, approximately three natives move out. Note, however, that one cannot reject the hypothesis that the coefficient is equal to one. The comparison of wage regressions estimated at the city level versus the state level, presented in Section IV.D, provides stronger evidence on the existence of displacement effects. C. Price Effects A first approach to the study of the effect of low-skilled immigrants on prices of nontraded goods is to look only at the prices of services that use their labor intensively. The services included in the empirical analysis of this section are those for which I have data both on prices and on the composition of employment, and whose intensity in the use of lowskilled immigrant labor was at least 9 percent in 1980.12 These are laundry and dry cleaning, shoe repair, babysitting, housekeeping, barber shops, and other household services (including gardening). Ideally, I 12 I use the 1980 data to avoid endogeneity of technology choices. I chose 9 percent as the threshold because it is a standard deviation above the average across industries. low-skilled immigration and u.s. prices 399 would have run a separate regression for each service and estimated a separate effect of the immigration shock and separate city fixed effects. Because I have so few observations (30 cities and three decades), I pool all indexes in the same regression and restrict the city fixed effects and the effect of immigration to be equal across all services.13 I then control for industry fixed effects. The general estimating equation is ln Piht p v ln LS Workersit ⫹ fi ⫹ zh ⫹ wrt ⫹ iht , Labor Forceit (19) where i is city, h industry, r region, and t decade. The terms fi, zh, and wrt represent city, industry, and region#decade fixed effects, respectively. The linear fixed effects in equation (19) control for time-invariant differences in price levels across cities and across industries and for regionspecific shocks. Note that I use ln (LS Workersit/Labor Forceit) as the explanatory variable. There are a couple of reasons for this choice. First, it is a simplified version of the price equations’ main explanatory variable derived from the model.14 Second, the magnitude of the elasticity of prices with respect to immigration will depend on the share of immigrants in the low-skilled labor supply, which, relative to the share of lowskilled workers, varies significantly by city.15 Table 5 reports the ordinary least squares (OLS) and instrumental variable (IV) estimation of equation (19). The OLS coefficient for the immigration variable is negative and statistically significant. However, as has been emphasized in the immigration literature, the magnitude of the cross-sectional correlation between immigrant inflows and economic outcomes is likely to be biased upward; immigrants choose their loca13 Results are robust to excluding one service at a time. See App. table C1 for this and other robustness checks. 14 The term ln (LS Workersit/Labor Forceit ) assumes that r p 1 in the theoretical model. In tables 5, 8, and 10, I replace r p 0.8 (j p 5 ) and r p 0.5 (j p 2). Results change very little. 15 To derive the elasticity of variable y to low-skilled immigration, the chain rule is used: LS Workersit d d ln y d ln y Labor Forceit p # d(ln LS Immigrants) LS Workersit d(ln LS Immigrants) d Labor Forceit ( )( ) dLS Natives LS Immigrants . dLS Immigrants LS Immigrants ⫹ LS Natives Note that the share of immigrants in the low-skilled labor supply varies significantly by city. I use its value for each city from the census (and set dLS Natives/dLS Immigrants p 0) to calculate the city-specific immigration effect of the low-skilled immigration flow of the period 1980–2000. I report the weighted average across cities of these effects unless explicitly noted. ⯝v# 1⫹ / .5 1/.5 (3) (4) (5) No No Yes .639 540 Yes No Yes .641 540 Yes Yes Yes .645 540 No No Yes .627 540 Yes No Yes .620 540 ⫺.167 ⫺.126 ⫺.247 ⫺.479 ⫺.638 (.072)** (.091) (.118)** (.135)*** (.207)*** (2) OLS Yes No Yes .580 540 ⫺.249 (.118)** (6) (7) Yes No Yes .617 540 ⫺.615 (.205)*** IV Yes No Yes .606 540 ⫺.578 (.210)*** (8) Yes No No .637 486 ⫺.533 (.199)*** (9) Note.—Services included in the regression are babysitting, housekeeping, gardening, dry cleaning, shoe repair, and barber shops. All regressions include city, industry, and decade fixed effects. Standard errors clustered at the city#decade level are reported in parentheses. The number of observations is 540 (30 cities, six industries, and three time periods). * Significant at the 10 percent level. ** Significant at the 5 percent level. *** Significant at the 1 percent level. Other controls: Region#decade fixed effects ln(Employment) Includes California R2 Observations .5 / .8 1/.8 ln[(LS Natives ⫹ LS Immigrants ) Labor Force] .8 ln[(LS Natives ⫹ LS Immigrants ) Labor Force] ln(LS Immigrants/Labor Force) Main explanatory variable: ln[(LS Natives ⫹ LS Immigrants)/Labor Force] (1) TABLE 5 The Effects of LS Immigration on Prices of Immigrant-Intensive Industries, 1986–2000 Dependent Variable: ln(Price Index) low-skilled immigration and u.s. prices 401 tion, at least in part, on the basis of the economic opportunities that cities offer. The results are generally invariant to the inclusion of controls for economic trends that potentially attract immigrant flows. For example, the coefficient of column 2 of table 5, which includes region-specific time trends, is very similar to the coefficient of column 1. The inclusion of the log of the level of employment (col. 3) increases the magnitude of the immigration concentration coefficient, supporting the hypothesis that OLS coefficients are biased upward because immigrant flows are correlated with unobserved economic conditions. This regression is, however, potentially flawed since employment is likely to be endogenous. Columns 4–9 of table 5 present the IV estimates of equation (19). The results suggest that an increase of 10 percent in the share of lowskilled workers in the labor force of a city reduces the prices of services that intensively use immigrant labor by 4.8–6.3 percent. Given that today, on average, low-skilled immigrants represent 40 percent of the lowskilled labor supply of a city, a 10 percent increase in the number of low-skilled immigrants will reduce prices of immigrant-intensive services by close to 2 percent. For example, the low-skilled immigration shock experienced by the United States in the period 1980–2000 should have reduced the prices of these services, on average, by approximately 9 percent. When all the cities in California are excluded from the regression, the coefficient becomes smaller but is still highly statistically significant. I can use my model from the previous section to compare my econometric estimates with the theoretical predictions. Equation (11) from the model suggests that v̂ ⯝ ⫺(1 ⫺ a), the Cobb-Douglas coefficient for the low-skilled labor aggregate in the production function of the nontraded good. Given that table 2 suggests that around 30–40 percent of all workers in the immigrant-intensive services are low skilled and that capital is not heavily used in the production of these services, v̂ p ⫺0.64 from table 5 is reasonably consistent with the theoretical predictions. As a specification check, I also estimate equation (19) for five other groups of goods and services: nontraded goods with higher than average (but not highest) use of low-skilled immigrant labor, nontraded goods with lower than average use of this input, and traded goods divided into the three categories of “immigrant labor intensity.”16 Assuming no demand effects of low-skilled immigration, the effect on other nontraded goods not included in table 5 should have a significantly smaller magnitude than on goods that use immigrant labor intensively. Also, by 16 See App. table A1 for a classification of traded and nontraded goods into these categories. 402 journal of political economy TABLE 6 Price Effects of Low-Skilled Immigration on Various Groups of Goods and Services Dependent Variable: ln(Price Index) Coefficient: ln[(LS Natives ⫹ LS Immigrants)/ Labor Force] Group of Goods and Services 1. Nontraded, intensive in low-skilled foreign labor 2. Nontraded, moderate use of low-skilled foreign labor 3. Nontraded, low use of low-skilled foreign labor 4. Traded, intensive in lowskilled foreign labor 5. Traded, moderate use of low-skilled foreign labor 6. Traded, low use of lowskilled foreign labor OLS ⫺.126 (.091) IV Number of Industries ⫺.638 (.207)*** 6 ⫺.170 (.171) 6 .128 (.055)** .066 (.107) 22 .020 (.076) .211 (.149) 16 .045 (.050) .139 (.098) 14 ⫺.052 (.096) .068 (.153) 10 .051 (.094) Note.—All regressions include city, industry, and region#decade fixed effects. Standard errors clustered at the city#decade level are reported in parentheses. * Significant at the 10 percent level. ** Significant at the 5 percent level. *** Significant at the 1 percent level. definition, low-skilled immigration at the local level should not have any effect on the prices of traded goods. In reality, most goods, especially when considered from the point of view of the consumer, are not purely tradable; there is always a part of the price that reflects the retailer’s handling costs, and these costs are likely to be affected by local relative endowments. However, for most goods, these handling costs represent only a small share of the final price. For example, Barsky et al. (2003) estimate an upper bound for the retailing costs of grocery goods, such as cookies and soft drinks, of approximately 15 percent. Also, assuming that the effect of retailing costs on prices of goods is not systematically related to the percentage of low-skilled employees producing the good, it appears that even if the traded goods are affected by local endowments, that effect should not be especially large for the group of goods that use immigrant labor intensively in their production process. The results presented in table 6 are in line with the theoretical predictions and suggest that in table 5 I am actually capturing the causal effect of immigration on prices through changes in labor supplies. The low-skilled immigration and u.s. prices 403 coefficient on low-skilled immigrant concentration on the prices of nontraded goods that use immigrant labor moderately is negative but has a smaller magnitude and is not statistically significant. The coefficients in the equations for the prices of traded goods are positive but not statistically distinguishable from zero. The estimates for these groups of goods also suggest that other mechanisms through which low-skilled immigrants might affect the prices of goods and services (e.g., changes in demand) are not very large, or at least are not captured by the empirical analysis of the present paper. An alternative specification for nontraded goods that should yield results similar to those of tables 5 and 6 and directly tests for the labor supply mechanism is the following: ln Piht p v ln LS Workersit LS Immigrantsh ⫹b# Labor Forceit Workersh # ln LS Workersit ⫹ fit ⫹ lht ⫹ iht , Labor Forceit (20) in which I add an interaction of the immigrant concentration in the city with the share of total workers in the industry that were low-skilled immigrants (which proxies for the production technology of the good). The intuition is simple: a low-skilled immigrant shock to a given city should mostly affect the prices of goods and services that use their labor intensively (b ! 0). An advantage of this specification is that city#decade fixed effects can be included, making the identification assumption much harder to violate. I estimate equation (20) for the sample of all nontraded goods and services. The direction of the results (presented in table 7) is in line with tables 5 and 6. The direct effect of low-skilled immigrant concentration on the prices of nontraded goods is slightly negative but not statistically significant, and the interaction term is negative and marginally significant. The magnitudes, however, suggest smaller effects. Discrepancies might come from the additional restrictions imposed in equation (20), for example, that the city fixed effects do not vary by industry group. When equation (20) is estimated for traded goods, both v and b are small and not significant statistically (see cols. 4 and 5 in table 7). D. Wage Effects The estimated coefficients from the previous subsection demonstrate that low-skilled immigration has an effect on the prices of low-skilled immigrant-intensive services; this subsection explores the channels through which the effect is likely to take place. Given the nature of the 404 journal of political economy TABLE 7 Production Technology and the Effects of Low-Skilled Immigration on Prices Dependent Variable: ln(Price Index) All Nontraded Main Explanatory Variables OLS (1) IV (2) ln(LS Workers/Labor Force) .075 (.048) ⫺.063 (.108) ⫺.144 (.180) No 3,058 ⫺.836 (.495)* No 3,058 % LS Immigrants in Production#Ln(LS Workers/ Labor Force) City#decade fixed effects Observations All Traded IV (3) IV (4) IV (5) .173 (.088)* ⫺.836 (.500)* Yes 3,058 ⫺.395 (.414) No 3,597 ⫺.394 (.417) Yes 3,597 Note.—All regressions include city, industry#decade, and region#decade fixed effects. Standard errors clustered at the city#decade level are reported in parentheses. * Significant at the 10 percent level. ** Significant at the 5 percent level. *** Significant at the 1 percent level. services included in the regressions of table 5 (very labor-intensive production processes, particularly of the unskilled type), the obvious channel through which the prices go down after a low-skilled immigration shock is a reduction in wages. However, as mentioned in the introduction, all the studies that have used cross-city variation for the identification of wage effects have found negligible effects of immigrant groups on the wages of competing natives, including the very low skilled. The existing evidence in the literature on the wage effects of new waves of immigrants on older immigrants does not help in clarifying the matter; it is scarce and inconclusive.17 The model from Section III predicts that the strong evidence of no wage effects on natives invalidates the wage mechanism for the reduction in prices if low-skilled natives and low-skilled immigrants are perfect substitutes in production. There are good reasons, however, to think that low-skilled immigrants and natives are far from being perfect substitutes. For example, Census data for 2000 show that more than 80 percent of the low-skilled immigrants who arrive each year in the United States speak very little English and that, even after 10 years in the country, still 60 percent report not speaking English or not speaking it well. English skills matter for occupational choice: Cortes (2006) finds a strong negative correlation between the language skills intensity of a 17 The three papers that study the impact of immigration on earlier immigrants are Card (1990), LaLonde and Topel (1991), and Borjas (2003). Card finds no significant negative effect of an immigration shock on the labor outcomes of earlier immigrants. LaLonde and Topel find that higher immigration modestly lowers the wages of more recent immigrant cohorts, and Borjas finds a sizable, but not statistically significant, negative effect. low-skilled immigration and u.s. prices 405 low-wage occupation and the ratio of immigrants to natives who work in that occupation. Also, conditional on not having a high school diploma, the average years of education of immigrants is significantly lower than that of natives, and the quality of each year of education is potentially higher in the United States. The legal status of most low-skilled foreigners working in the United States is the final reason for which natives and immigrants might not be perfect substitutes. To empirically test my hypothesis that lower wages drive the reduction in prices, but that the wages of competing immigrants are affected significantly more than those of natives because natives and immigrants are far from perfect substitutes, I run wage regressions for different groups of the population. I use the following econometric specification: ln wnit p v e ln LS Workersit ⫹ X n Le ⫹ Wit Se ⫹ fie ⫹ wrte ⫹ eijt, Labor Forceit (21) where e is the group of the population I am analyzing, n a low-skilled worker, i a city, r a region, and t a decade. The term X n represents individual-level characteristics, namely, age, age squared, sex, a black dummy, and a Hispanic dummy. The term Wit represents city time-varying variables, specifically the percentage of males in the low-skilled labor force. The linear fixed effects in equation (21) control for time-invariant differences in labor outcomes across cities and for region-specific shocks. Wage data for the estimation of equation (21) come from the 1980, 1990, and 2000 Censuses. The sample is restricted to workers who reported a positive annual labor income, a positive number of total weeks worked last year, and a positive number of “usual hours worked per week.” Top-coded incomes were multiplied by 1.5, and hourly wages were adjusted for inflation. Workers with a wage per hour of less than $2.00 were excluded from the sample. The estimated v e ’s are reported in table 8. Panel A in the table estimates equation (21) for all native high school dropouts. In line with the previous cross-city literature, under most specifications, I find a negative but small and insignificant effect of low-skilled immigration on wages. I find a larger and marginally significant effect on the wages of female native workers (col. 8). I then estimate the wage effect of recent flows of immigrants on the wages of low-skilled immigrant workers who have been in the United States for at least 10 years. I find significant negative effects when individuals of both sexes are included in the specification (table 8, panel B). Columns 7 and 8 of panel B show that the result is driven by the female sample. I present two pieces of evidence that suggest that the male coefficient’s ⫺.085 (.041)*** No Yes .134 117,049 .023 (.054) No Yes .238 509,975 ⫺.116 (.050)** No Yes .134 117,049 ⫺.044 (.073) No Yes .238 509,975 IV rp1 (2) IV r p .8 (5) ⫺.114 (.069) Yes No .242 456,739 ⫺.048 (.069) Yes Yes .239 509,975 ⫺.047 (.068) Yes Yes .239 509,975 IV r p .5 (6) ⫺.123 (.059)** Yes Yes .135 117,049 ⫺.043 (.077) Yes No .141 71,913 ⫺.133 (.064)** Yes Yes .135 117,049 ⫺.160 (.076)** Yes Yes .135 117,049 B. Low-Skilled Previous Immigrants ⫺.050 (.071) Yes Yes .239 509,975 IV rp1 (4) A. Low-Skilled Natives All IV rp1 (3) .042 (.069) Yes Yes .124 71,477 ⫺.045 (.082) Yes Yes .280 306,569 IV rp1 (7) Male ⫺.292 (.059)*** Yes Yes .055 45,572 ⫺.099 (.058)* Yes Yes .097 203,406 IV rp1 (8) Female Source.—1980, 1990, and 2000 Census. Note.—City and decade fixed effects are included in all specifications. Controls at the individual level are age, age squared, gender, black dummy, and Hispanic dummy. Other controls are % males in the native group studied. Regressions for immigrants include dummies for Hispanic group (Mexican, Cuban, etc.) and the percentage of each Hispanic group in the immigration population of the city. Standard errors clustered at the city#decade level are reported in parentheses. All regressions are weighted using the census person weight. * Significant at the 10 percent level. ** Significant at the 5 percent level. *** Significant at the 1 percent level. Region#decade fixed effects Includes California R2 Observations ln(LS Nativesr ⫹ LS Immigrantsr)1/r Region#decade fixed effects Includes California R2 Observations r 1/r ln(LS Natives ⫹ LS Immigrants ) r OLS rp1 (1) TABLE 8 The Effects of Low-Skilled Immigration on the Hourly Wages of Low-Skilled Workers Dependent Variable: ln(Hourly Wage) low-skilled immigration and u.s. prices 407 TABLE 9 Labor Force Participation Statistics from the Census and Other Sources 1980 1990 2000 Current Population Survey 1999–2001 .815 (.388) .814 (.389) .675 (.468) .830 (.375) .827 (.378) .492 (.500) .506 (.500) .431 (.495) .482 (.500) .483 (.500) .678 (.467) .604 (.489) .517 (.500) .552 (.497) .484 (.500) .683 (.465) .618 (.486) .506 (.500) .574 (.495) .513 (.500) .862 (.345) .858 (.349) .741 (.438) .899 (.301) .862 (.345) .827 (.378) .866 (.340) .785 (.411) .833 (.301) .838 (.368) .908 (.289) .907 (.290) .864 (.343) .900 (.299) .895 (.307) Census Low-skilled male immigrants Low-skilled female immigrants Low-skilled male natives Low-skilled male Hispanic natives High-skilled male immigrants Some college male immigrants College graduate male immigrants American Community Survey 2005–6 magnitude and significance are due to data issues and do not represent a real effect. First, I estimate equation (21) for the sample of low-skilled male immigrants separately for the two decades included in the analysis and find that the problematic result comes from the 1990–2000 regression. The wage effect for this period is positive and highly significant.18 Simple descriptive statistics of labor force participation reported by decade, shown in table 9, suggest that there is a large degree of misreporting in the 2000 Census, especially from low-skilled male immigrants.19 Second, I estimate equation (21) for the native groups who are similar to low-skilled immigrants in terms of race and English proficiency and therefore are more likely to compete directly with immigrants in the labor market. My assumption is that the effect of lowskilled immigration on the wages of these groups should provide a lower 18 The coefficient for 1980–90 is ⫺0.146 (0.07) and for 1990–2000 is 0.714 (0.149). The coefficient for the sample of low-skilled native Hispanic males for the period 1990–2000 is ⫺0.474 (0.280). 19 A likely explanation for the underreporting of labor force participation is that the 2000 Census included many more illegal immigrants than the previous censuses, and undocumented immigrants might lie about their labor force status. The price effects estimates are robust to using as the explanatory variable the total number of low-skilled immigrants, and not just those who reported being in the labor force. See App. table C1. 408 journal of political economy bound for the wage effects on other low-skilled immigrants. As observed in table 10, panel A, the wage effects for native Hispanics, both female and male, are negative and statistically significant and have a magnitude similar to those for the impact on female immigrants. Moreover, the coefficient is significantly larger, though not very precisely estimated (the number of observations drops significantly), for low-skilled Hispanic natives who reported that they do not speak English very well. Taking the estimated coefficients for these two groups to proxy for the effect on immigrants already in the country implies that, at current immigration levels, a 10 percent increase in the share of low-skilled immigrants in the labor force of a city will reduce the wages of lowskilled immigrants already present in the United States by between 2 and 4 percent. Notice that this number is reasonably consistent with the price effect of immigration on immigrant-intensive services. As mentioned in the introduction, the estimation of small and insignificant effects of low-skilled immigration on native wages using crosscity variation does not imply that immigrants have no effect on the labor outcomes of natives. If natives respond to immigration by moving to other cities, the full effect of immigration will not be captured by the local influx coefficient, which will provide only a lower bound (Borjas 2006). To check whether the wage effects at the local level are being attenuated by the native migration response, I estimate equation (21) at the state level and summarize the results in table 11. Columns 1 and 2 report the estimation when the sample is restricted to individuals living in the 30 cities included in the price regressions; columns 4 and 5 include all cities. Two observations are worth mentioning. First, wage effects at the state level are always larger than at the city level for all groups of low-skilled workers, particularly for the native population. This result suggests that workers do move as a response to immigration shocks and that immigrants do have a negative effect on the wage of the typical low-skilled native. It also suggests that the median native’s migration decision is more responsive to city wage differences than that of native Hispanics and immigrants. Second, even at the state level, the wage effects of immigrants are much larger for previous immigrants and native Hispanics than for the average native, suggesting again that the two labor inputs are not perfect substitutes. The state-level estimates will still not capture the full wage effects of immigration if workers move across states. Ideally, wage effects should be estimated at the national level; unfortunately, given my empirical strategy, this will imply not including year fixed effects and not using an instrument to solve for the omitted variable bias. Exploiting variation in immigrant shocks within education#experience cells, Borjas (2006) ⫺.035 (.089) No Yes .121 17,647 IV rp1 (4) IV r p .8 (5) IV r p .5 (6) ⫺.301 (.143)** Yes Yes .147 58,124 ⫺.328 (.156)** Yes No .137 42,348 ⫺.298 (.147)** Yes Yes .147 58,124 ⫺.295 (.174)* Yes Yes .147 58,124 A. Low-Skilled Native Hispanics IV rp1 (3) ⫺.271 (.151)* Yes Yes .170 35,978 IV rp1 (7) ⫺.433 (.177)** No Yes .119 17,647 ⫺.637 (.370)* Yes Yes .121 17,647 ⫺.728 (.469) Yes No .116 14,237 ⫺.545 (.304)* Yes Yes .121 17,647 ⫺.435 (.247)* Yes Yes .122 17,647 ⫺.578 (.336)* Yes Yes .115 11,439 B. Low-Skilled Native Hispanics with Low English Proficiency ⫺.297 (.123)** No Yes .145 58,124 IV rp1 (2) Male ⫺.739 (.559) Yes Yes .043 6,208 ⫺.331 (.178)* Yes Yes .058 22,146 IV rp1 (8) Female Source.—1980, 1990, and 2000 Census. Note.—City and decade fixed effects are included in all specifications. Controls at the individual level are age, age squared, gender, black dummy, and Hispanic dummy. Other controls are % males in the native group studied. Regressions for Hispanics include dummies for Hispanic group (Mexican, Cuban, etc.) and the percentage of each Hispanic group in the native Hispanic population of the city. Standard errors clustered at the city#decade level are reported in parentheses. All regressions are weighted using the census person weight. * Significant at the 10 percent level. ** Significant at the 5 percent level. *** Significant at the 1 percent level. Region#decade fixed effects Includes California R2 Observations r 1/r ln(LS Natives ⫹ LS Immigrants ) r Region#decade fixed effects Includes California R2 Observations ⫺.013 (.090) No Yes .146 58,124 ln(LS Nativesr ⫹ LS Immigrantsr)1/r OLS rp1 (1) All TABLE 10 Effects of Low-Skilled Immigration on the Hourly Wages of Low-Skilled Native Hispanics Dependent Variable: ln(Hourly Wage) ⫺.165 (.073)** ⫺.338 (.150)** ⫺.206 (.101)* ⫺.469 (.094)*** 20 ⫺.050 (.071) ⫺.301 (.143)** ⫺.123 (.059)** ⫺.292 (.059)*** 30 45,572 117,049 58,124 509,975 Observations ⫺.013 (.058) ⫺.221 (.093)** ⫺.209 (.057)*** ⫺.292 (.068)*** 123 City Level ⫺.240 (.088)*** ⫺.376 (.141)*** ⫺.359 (.097)*** ⫺.469 (.083)*** 37 State Level 65,728 169,646 101,726 906,780 Observations All Cities Sample Source.—1980, 1990, and 2000 Census. Note.—City/state and region#decade fixed effects are included in all specifications. Controls at the individual level are age, age squared, gender, black dummy, and Hispanic dummy. Other controls are % males in the native/immigrant group studied. Regressions for Hispanics/immigrants include dummies for Hispanic group (Mexican, Cuban, etc.) and the percentage of each Hispanic group in the Hispanic/immigrant population of the city/state. Standard errors clustered at the city/state#decade level are reported in parentheses. All regressions are weighted using the census person weight. * Significant at the 10 percent level. ** Significant at the 5 percent level. *** Significant at the 1 percent level. Number of cities/states Low-skilled previous immigrants (females) Low-skilled previous immigrants Low-skilled native Hispanics Low-skilled natives State Level City Level 30-City Sample TABLE 11 Effects of Low-Skilled Immigration on Wages of Low-Skilled Workers: City vs. State Levels Dependent Variable: ln(Hourly Wage) low-skilled immigration and u.s. prices 411 estimates that native migration attenuates the measured impact of immigration on wages in the state labor market by 40 percent.20 It is important to emphasize, however, that the primary purpose of estimating the wage equations at the city level was to test if indeed wages are the main channel through which prices of nontraded goods are affected by local shocks to immigration. The fact that I find wage effects at the city level for previous immigrants and native Hispanics and that their magnitudes are reasonably consistent with the price effects is key for my story. The wage estimates at the city level, even if not capturing the full effects, also imply that immigrants and natives cannot be perfect substitutes. If they were, wages should be affected equally at the local level, regardless of different propensities to migrate. Back-of-the-envelope calculations using equations (15) and (16) and my estimates for the local wage effects for low-skilled immigrants and natives suggest a lower bound for the elasticity of substitution between the two labor inputs of approximately 4. My estimate is consistent with the findings of Ottaviano and Peri (2006), who estimate an elasticity of substitution between 5 and 10. V. Purchasing Power Calculations The previous section demonstrates how low-skilled immigration affects prices of nontraded goods and wages at the city level. This evidence alone is not sufficient to determine how natives’ purchasing power is affected; data on native preferences are needed. This section combines data on consumption patterns from the CEX with the price and wage effects obtained in Section IV to estimate how natives’ purchasing power was changed by the immigration wave of the years 1980–2000. Natives of all skill levels benefit from low-skilled immigration through the reduction in the nontraded goods component of the cost of living. I use the expenditure shares from the 2000 CEX to calculate changes in the Paasche index caused by the immigration influx of the past two decades and interpret these changes as the price benefits from immigration. Column 1 of table 12 shows the share of total expenditures devoted to household services by different education groups. As expected, the share increases with education levels and is almost a third higher for very educated natives compared with high school dropouts. Even for the very high skilled, however, the share is very small (4.3 percent), such that the overall effect on purchasing power is not large: 20 I cannot use the variation in Borjas (2006) to estimate national-level effects because for low-skilled workers, people of different ages are very substitutable. When I control for decade#city fixed effects, the coefficient of the immigrant shock defined at the education#city#age level in eq. (21) is small and not statistically significant. This is true for all low-skilled groups. Results are available on request. 3.2 3.2 3.4 3.7 3.8 4.3 Education of Household Head Less than high school: Median low-skilled native Low-skilled native Hispanic High school graduate Some college College graduate Graduate education Note.—Coefficients from tables 5, 8, and 10 were used for these calculations. Expenditure Share of ImmigrantIntensive Services (1) ⫺9.2 ⫺9.2 ⫺9.2 ⫺9.2 ⫺9.2 ⫺9.2 Simulated Change in Price of ImmigrantIntensive Services (2) ⫺.29 ⫺.29 ⫺.31 ⫺.33 ⫺.35 ⫺.40 Simulated Change in Price Index 1980–2000 (3) ⫺.72, ⫺1.43 ⫺4.32 .00 .00 .00 .00 Simulated Change in Wages 1980–2000 (4) ⫺.43, ⫺1.14 ⫺4.03 .31 .33 .35 .40 Simulated Change in Purchasing Power 1980–2000 (5) TABLE 12 Simulation Exercise: Price and Wage Effects of the Low-Skilled Immigration Influx of the Period 1980–2000 (%) low-skilled immigration and u.s. prices 413 the immigration shock of the 1980s and 1990s decreased the cost of the consumption basket between 0.29 percent for native high school dropouts and 0.40 percent for natives with graduate education. Lower prices come at a cost. As discussed in the previous section, the wages of low-skilled natives of Hispanic origin are reduced by the inflows of foreign-born high school dropouts to a city. For the average lowskilled native, however, the local effect is small. If one takes the largest estimate (⫺0.099 for the female sample), the magnitude suggests that the low-skilled immigration wave of the past two decades decreased lowskilled native wages by a maximum of 1.43 percent. This number increases to 4.2 percent for low-skilled natives of Hispanic origin and with low English proficiency. I combine the cost-of-living effects and the wage effects to calculate the net impact of low-skilled immigration on natives’ purchasing power by skill group. As observed in table 12, low-skilled natives’ purchasing power was reduced by between 0.43 percent and 1.14 percent for the typical native and close to 4 percent for natives of Hispanic origin. However, high school graduates, workers with some college, and college graduates benefited: their purchasing power increased between 0.31 percent and 0.4 percent. Given that low-skilled natives represent a small fraction of all native workers, the average net benefit for the native population was positive.21 VI. Conclusion A large body of literature analyzes the impact of immigration on the employment opportunities of native workers and the costs it imposes on taxpayers. With the exception of Borjas (1995), this literature has not addressed the gains that immigration brings to the native population. The study of the benefits from immigration is important because the contrast between benefits and costs (not only economic, of course) informs decisions about immigration policy. This paper contributes to the immigration literature by estimating the impact of low-skilled immigration on prices, wages, and the purchasing power of natives. I find that low-skilled immigration benefits the native population by decreasing the nontraded goods component of the cost of living. At current U.S. immigration levels, a 10 percent increase in the average city’s share of low-skilled immigrants in the labor force decreases the price of immigrant-intensive services such as housekeeping and gar21 These numbers are likely to underestimate the benefits from low-skilled immigration because they do not take into account the complementarities between low-skilled labor and capital and between low- and high-skilled labor. However, the estimates abstract from any effects from the demand side. See Saiz (2003, 2007) for evidence on the effects of immigration on rents. 414 journal of political economy dening by 2 percent. A simple theoretical model and my wage estimates suggest that wages are a likely channel through which these effects take place. However, wage effects are significantly larger for low-skilled immigrants than for the median low-skilled native, implying that the two are imperfect substitutes. My results imply that the low-skilled immigration wave of the period 1980–2000 increased the purchasing power of high-skilled workers living in the 30 largest cities by an average of 0.32 percent and decreased the purchasing power of the typical native high school dropouts by a maximum of 1 percent and of Hispanic lowskilled natives by 4.2 percent. I conclude that, through lower prices, low-skilled immigration brings positive net benefits to the U.S. economy as a whole but generates a redistribution of wealth. Because of the focus on city-level outcomes, this paper has looked at prices of only nontraded goods and services. Low-skilled immigration is also likely to have effects on the prices of traded goods, but these will occur at an aggregate, national level. A theoretical and empirical exploration of this issue is needed in order to have a complete assessment of the effects of low-skilled immigration. Utilities: Electricity Utility natural gas services Telephone services, local charges Water and sewage maintenance Cable TV Garbage and trash collection Medical services: Hospital and other medical care services Physicians’ services Dental services Eyeglasses and eye care Services by other medical professionals Education: College tuition and fees Elementary and high school tuition Child day care Other tuition and fees Household services: Food away from home Babysitting Domestic service Nontraded Goods and Services Appendix A 2 1 1 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 Group Traded Goods and Services Food: Cereals Bakery products Beef and veal Pork Other meats Fish and seafood Fresh milk and cream Processed dairy products Fresh fruits Fresh vegetables Processed fruits Processed vegetables Sugar and sweets Carbonated drinks Apparel and textiles: Apparel Footwear Textile house furnishing Gadgets: Household appliances TV and sound equipment TABLE A1 Classification of Goods and Services 2 2 1 1 1 2 1 2 2 1 1 2 2 1 1 1 1 1 3 Group 416 2 1 3 3 2 2 3 3 3 3 3 1 2 3 1 1 Group Traded Goods and Services Toys, hobbies, etc. Photographic supplies and equipment Watches Sporting goods and equipment Information technology, hardware and services Supplies: Maintenance and repair commerce Toilet goods and personal care Laundry and cleaning products Household paper products Other: Intrastate telephone services Airline fares Other intercity transportation Fuel oil Furniture and bedding Tires New vehicles Prescription drugs and medical supplies Nonprescription drugs and medical supplies Reading materials School books and supplies Tobacco products 3 3 3 3 1 1 2 3 3 3 3 2 2 2 2 2 1 2 1 1 3 Group Note.—Group p 1 if low-skilled immigrant share in industry’s employment is greater than 9 percent in 1980; group p 2 if low-skilled immigrant share in industry’s employment is between 4 and 9 percent in 1980; Group p 3 if low-skilled immigrant share in industry’s employment is less than 4 percent in 1980. Other household services (including gardening) Appliance and furniture repair Care of invalids, elderly at home Other apparel services (including shoe repair) Laundry and dry cleaning Other: Beauty parlors Barber shops Tenants’ insurance Automobile insurance Automotive repair Automotive maintenance and service Intracity transportation Admissions (movies etc.) Legal fees Cemetery lots and funeral expenses Financial services Nontraded Goods and Services TABLE A1 (Continued ) 417 j (1) (2) .405 (.285) Yes Yes .972 90 (3) .659 (.287)** Yes No .970 81 Note.—OLS estimates. City and decade fixed effects are included in all the regressions. Robust standard errors are reported in parentheses. * Significant at the 10 percent level. ** Significant at the 5 percent level. *** Significant at the 1 percent level. .566 (.240)** No Yes .967 90 .366 (.054)*** No Yes .976 90 (4) .280 (.063)*** Yes Yes .980 90 (5) .299 (.070)*** Yes No .979 81 (6) ln[(LS Immigrants ⫹ LS Natives)/ Labor Force] Dependent Variable ln(LS Immigrants/Labor Force) TABLE B1 First Stage: 1986, 1990, and 2000 ji1970 /Immigrantsj1970 ) # LS Immigrantsjt ] Region#decade fixed effects Includes California R2 Observations ln [ 冘 (Immigrants Appendix B TABLE B2 First Stage: Alternative Functional Form Dependent Variable: LS Immigrants/Labor Force 冘 (Immigrants (1) (2) (3) .297 (.075)*** .217 (.073)** .831 (.218)*** ⫺.279 (.075)*** No Yes .967 90 ⫺.211 (.073)*** Yes Yes .976 90 -2.168 (.627)*** Yes No .971 81 ji1970 /Immigrantsj1970 ) # LS j Immigrantsjt 冘 [ j (Immigrantsji1970 /Immigrantsj1970 ) # LS Immigrantsjt]2 Region#decade fixed effects Includes California R2 Observations Note.—OLS estimates. Included years are 1980, 1990, and 2000. City and decade fixed effects are included in all the regressions. Robust standard errors are reported in parentheses. * Significant at the 10 percent level. ** Significant at the 5 percent level. *** Significant at the 1 percent level. TABLE B3 Countries Included in the Construction of the Instrument Albania Argentina Australia Austria Azores Belgium Belize Bolivia Brazil Bulgaria Canada Chile China Colombia Costa Rica Cuba Czechoslovakia Denmark Dominican Republic Ecuador Egypt El Salvador England Finland France Germany Greece Guatemala Haiti Honduras Hungary India Iran Ireland Israel Italy Jamaica Japan Jordan Korea Latvia Lebanon Lithuania Mexico Netherlands New Zealand Nicaragua Northern Ireland Norway Pakistan Panama Paraguay Peru Philippines 418 Poland Portugal Romania Russia Scotland South Africa Spain Sweden Switzerland Syria Trinidad and Tobago Turkey Uruguay Venezuela Vietnam Wales Yugoslavia 419 Observations Excludes Main explanatory variable: ln[(LS Natives ⫹ LS Immigrants)/Labor Force] Observations Excludes ⫺.618 (.241)** Top 3 cities’ share of Mexicans in labor force 486 (1) 450 ⫺.628 (.213)*** Gardening and other services 450 (3) (5) ⫺.640 (.274)** Top 4 cities’ share of Mexicans in labor force 468 (2) 486 ⫺.576 (.267)** LA, NY, and Miami (3) (6) 450 450 450 ⫺.679 ⫺.673 ⫺.535 (.230)*** (.235)*** (.174)*** Shoe repair Laundry and Barber shops dry cleaning (4) B. Specifications Excluding Cities with Many Immigrants 450 ⫺.602 (.206)*** Housekeeping (2) A. Specifications Excluding Immigrant-Intensive Services One by One ⫺.711 (.245)*** Babysitting (1) TABLE C1 Robustness Checks to Instrumental Variables Price Regressions Dependent Variable: ln(Price Index) Main explanatory variable: ln[(LS Natives ⫹ LS Immigrants)/Labor Force] Appendix C 360 ⫺.567 (.161)*** 1980 (1) 540 ⫺.501 (.179)*** Uses 1980 immigrant variables and 1986 prices (2) ⫺.427 (.162)*** Replaces LS immigrants in labor force with all LS immigrants 540 (3) Note.—Services included in the regressions are babysitting, housekeeping, gardening, dry cleaning, shoe repair, and barber shops. All regressions include city, industry, and region#decade fixed effects. Standard errors clustered at the city#decade level are reported in parentheses. The four cities with the largest share of Mexicans in the labor force are Los Angeles, San Diego, Dallas, and Houston. 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