Fixed Capital Stock Depreciation in Developing Countries: Some Evidence from Firm Level Data Yisheng Bu1 Liberty Mutual Group 175 Berkeley Street, S3B Boston, MA 02116 USA This Version: December 2004 1 Mailing address: Liberty Mutual Group, 175 Berkeley Street, S3B, Boston, MA 02116, USA. Tel: +1617-894-4713. Email address: yisheng.bu@libertymutual.com. The author is indebted to George von Furstenberg and two anonymous referees for their review, very valuable comments and suggestions. The author is solely responsible for any remaining errors and omissions. Fixed Capital Stock Depreciation in Developing Countries: Some Evidence from Firm Level Data Previous growth accounting studies suggest severe capital underutilization and mismeasurement of the stocks of capital in some developing countries. Using the firm level data sets from the World Bank surveys, this paper estimates the economic depreciation rates of fixed capital stocks in the manufacturing industries of seven developing countries. The findings indicate that the stocks of fixed capital may depreciate at higher rates in these countries, as compared with the normal rates usually assumed for advanced industrial countries. This study also discusses the economic and social forces that may influence the incentive to maintain capital appropriately and the implications of high depreciation for the total factor productivity [TFP] growth estimates and volatility of capital accumulation. JEL Classification: E22, O10 2 The theoretical foundation for the measurement of economic depreciation rates and stocks of fixed capital has been well established in a series of papers by Hulten and Wykoff [1981], Jorgenson [1989, 1996] and Hulten [1990]. The empirical application of this measurement theory and methodology is still limited to the United States. Other advanced industrial countries have well developed methods for calculating gross stocks of capital but derive their net stock estimates by imposing certain strong assumptions about the capital depreciation patterns [OECD 1993, 2001]. Moreover, the methodologies for developed countries may not be appropriate for the measurement of stocks of fixed capital in developing countries, on account of either unavailability of relevant data (such as used asset prices in resale markets) or various inefficiency-related factors, such as excessive costs of capital creation and low productivity of capital expected even ex ante. All the international capital stock data sets that are currently available, which include the Penn World Table [PWT 5.6], and the ones used in Easterly and Rebelo [1993] and Nehru and Dhareshwar [1993], are constructed by applying a single common depreciation rate1 to aggregate or disaggregated investment series uniformly for all countries. However, as noted in PWT 5.6, the assumption of common depreciation rates across countries may be wrong because of country differences in the costs of capital maintenance and of new capital investment. By assuming equal depreciation rates across countries nonetheless, the conventional growth accounting studies have yielded misleading results and suggested severe capital underutilization and mismeasurement of the stocks of capital in some developing countries [Pritchett 1997, 1999]. By exploring available evidence on the resale value of fixed assets in selected developing countries, this paper intends to show that the economic depreciation rate in certain developing countries may well exceed the standard rate assumed in the growth studies. This paper uses the firm level survey data, collected by the World Bank in the 1990s, on total fixed assets, land and buildings, machinery and equipment in a group of selected countries in 3 Africa, East Asia and Southeast Asia. It obtains the implied rates of economic depreciation through the capital accumulation equation both for the individual firms and for all firms in the sample combined. The findings in this paper indicate that some developing countries, including the ones studied in this paper (Cote d’Ivoire, Ghana, Kenya, Zimbabwe, Indonesia, Philippines and South Korea), may depreciate their stocks of capital much faster than the U.S. economy and other OECD economies. High depreciation in the process of capital accumulation may then diminish the growth-promoting effect of high saving and investment rates in those countries as well as the effect of foreign aid. Abnormal depreciation rates observed for developing countries may be due to undermaintenance leading to premature discarding of capital. This is implied from the comparison with the depreciation rates calculated by directly using depreciation expenses recorded on the corporate financial account. High depreciation may be due to many economic and social forces. Government-provided investment incentives and capital underutilization may increase the marginal cost of capital maintenance or decrease its marginal benefit, both relative to the respective values of new capital investment, thus leading to faster capital depreciation. Other cases in which high depreciation results include corruption in capital goods procurement lowering the effectiveness of converting new investment into capital stock, or incompatible infrastructure facilities and technical services negatively affecting the rate of capital utilization. The findings in this paper on capital depreciation anomalies in certain developing countries have important implications for the total factor productivity [TFP] growth estimates obtained in previous growth accounting studies. Different capital depreciation profiles imply different rates of capital accumulation, and hence accounting for the higher rates of depreciation in constructing capital stock series would necessarily lead to comparatively higher estimates of TFP growth. This provides a possible explanation for the negative TFP growth rates reported for some developing countries in Pritchett [1997, 1999]. Another implication of higher depreciation 4 rates is higher volatility of capital stock growth. In the presence of much faster depreciation of existing capital, the stock of fixed capital becomes more vulnerable to the volatility of fixed investment and hence other macroeconomic variables in the economy. The structure of this paper is organized as follows. The next section presents and assesses the results from previous growth accounting studies and more importantly, stresses their implications for measuring the depreciation rate in developing countries. Sections 2 and 3 describe data sources and measurement methodology, respectively, and section 4 reports the empirical estimates of the economic depreciation rate for selected less developed countries in Africa, East Asia and Southeast Asia. Possible causes for capital undermaintenance in developing countries are discussed in section 5. Using conventional growth accounting regressions, section 6 investigates the implications of high depreciation for the estimates of TFP growth and the volatility of capital accumulation. Concluding remarks are given in section 7. 1. Capital Stock and Depreciation Rate Estimates for Developing Countries There are many authors who, through growth accounting studies or econometric regressions, find little contribution to economic growth of massive capital accumulation in most developing countries [Hulten 1996, Pritchett 1997, 1999, Easterly 1999, Devarajan et al. 2003]. For example, using the aggregate capital stock data2, Pritchett [1999: 28] finds that ‘over the last 30 years, 55 per cent of developing countries have measured TFP growth less than zero, with more than a quarter showing TFP as low as negative one per cent per annum.’ Negative TFP growth in an economy implies that the same amount of capital per unit of labour has been yielding progressively less output during the relevant period. It could be a direct indication of productivity decline, such as knowledge or skill loss, or destruction of institutional structures in developing countries, but one would view it as the outcome of many other factors to be discussed next. 5 Negative TFP growth observed for most developing countries may be explained by the mismeasurement of the stocks of capital by way of Cumulated, Depreciated, Investment Effort [CUDIE] in those countries. The concept of CUDIE, which is introduced in Pritchett [1997], refers to the accumulated investment spending less the accumulated capital depreciation calculated with standard depreciation rates. By imposing the assumption of zero minimum growth rate in TFP and solving for the growth of capital as the residual factor in growth accounting, Pritchett finds a much smaller growth in the effective stock of capital (which he calls the ‘implied’ rate of capital accumulation) than the CUDIE growth. Specifically, he finds that the regional average ratio of the ‘implied’ rate of capital accumulation to the CUDIE growth is 45.8% for the Middle East and North Africa, 48.8% for the Sub-Saharan Africa, 54% for South Asia, 72.2% for the Latin America and Caribbean, 94.5% for the fast growing Asian economies and 97.8% for OECD countries, respectively – see Table 5 in Pritchett [1997]. Even though these numbers cannot, in any way, accurately reflect the actual growth rates of the stocks of capital in the developing countries, they do indicate the mismeasurement of capital and its misleading implications for TFP growth. The mismeasurement of the stocks of capital for the developing countries may in turn be due either to excessive costs of capital creation3 or to high capital depreciation, both of which are being ignored in the CUDIE measure of the capital stock. The efficiency with which real capital is created from investment does differ greatly across countries, especially for capital creation in the public sector in countries with corrupt public agencies. For example, the cost (in 1985$) of constructing a kilometre of similar road ranges, across countries, from $771,068 in Honduras to $65, 277 in Sri Lanka, with a sample average of $287,359 [Canning and Fay 1995, and mentioned in Pritchett 1997]. Unusually high expenditure in creating a unit of capital may include the commission surcharge, in the forms of kickback, political contributions, or 6 nonpecuniary benefits demanded by public officials from private and public contractors for the project. Another cause for mismeasurement may relate to high rates of fixed capital stock depreciation in both public and private sectors. High depreciation of capital stock can result from lack of appropriate maintenance and premature discard. For privately used capital, the relative price of investing in new capital and maintaining existing capital may be distorted by favourable government policies toward investment, lack of competent maintenance and operational staff, unavailability of qualified repair parts, and so on. For publicly provided capital, high depreciation is even more pronounced on account of the accounting and budgetary treatment of depreciation4 in the government and various corruption-related factors. Declining TFP can also result if capital has been underutilized over a long period of time. The intensity with which the capital is utilized depends not only on the nature of the capital itself but also on many other complementary factors, such as technology, necessary following-up spending (for example, operating staff’s salaries and training), and supporting public services applied to the quasi-fixed capital. Moreover, capital underutilization could also lead to lowerthan-efficient level of capital maintenance and thus higher-than-normal capital depreciation, just as low maintenance expenditures may be responsible for extended downtime in a vicious cycle. The following sections intend to present empirical evidence supporting that the economic depreciation rates in certain developing countries are much higher, as compared to the standard rates assumed in the growth literature. 2. Data Sources and Description To empirically measure the economic depreciation rate for developing countries, I use the firm level data sets published by the World Bank on its website. The data sets cover a selected group of developing countries in Africa, East Asia and Southeast Asia. Numerous studies have 7 made use of these firm level data sets; however, no prior studies have ever used the asset prices in the data sets to measure capital depreciation rates in these developing countries. In this paper, the economic depreciation rate is estimated for four African countries (Cote d’Ivoire, Ghana, Kenya and Zimbabwe), one East Asian country (South Korea), and two Southeast Asian countries (Indonesia and Philippines). Table 1 gives details of data availability for measuring the economic depreciation rate for each type of assets in each country. For each type of assets (buildings, machinery and equipment, and total fixed assets), firms that have missing values for the relevant variables are dropped, while the remaining firms form new samples for which the economic depreciation rates are to be measured. For the African countries, Table 1 also reports the number of firms in the corresponding new samples that sold their fixed assets during the measurement period. {Insert Table 1 about Here} The firm level data sets came from questionnaire surveys conducted by the World Bank in the 1990s through interviews with firms. Similar sampling procedures and techniques were used in the survey across all sample countries, so that the data sets are comparable. For each country, firms were randomly selected from the industrial sectors that reflect the general composition of each country’s manufacturing sector and represent the largest sectors within each country’s manufacturing industries in terms of valued added, export and employment. In addition, firms of different size, age, location, ownership structure, and production orientation, and firms with foreign ownership (either in the form of joint venture or subsidiary of a foreign parent) were included in the sample for each country. For the Asian countries, the survey was conducted between October 1998 and March 1999. For the four African countries, the data sets were collected over three rounds of firm level interviews in successive years between 1992 and 1996, and the same sample of firms were intended to be included in all three surveys. Firms that 8 had dropped out of the previous sample for some reasons have been replaced with firms of the same size, from the same sector, and in the same region. The data sets on the African countries provide current market value of fixed assets, the selling price of assets that were sold, and the (nominal) value of new investment, for the time periods of up to six years. For some of the countries, the data sets also report the disaggregated market values of land and buildings, machinery and equipment. The current replacement values of total fixed assets and its disaggregated components are also available for Ghana, Kenya and Zimbabwe. Cote d'Ivoire is the only country for which the data set spans six years (1990-1995), while the time span of the data set is relatively short for the other three African countries: three years for Zimbabwe (1993-1995) and two years for both Ghana (1992-1993) and Kenya (19931994). For the Asian countries, the resale value of each type of asset is not available from the survey, and the net book values5 are used in the estimation as approximates. The data are available for the period 1996-1998 for South Korea and Philippines, and only for the period 19971998 for Indonesia. A summary of the variables used in the measurement of depreciation is provided in Table 2. {Insert Table 2 about Here} 3. Estimation Methodology The estimation methodology employed in this paper uses the direct estimates by firm managers of the current market values of land and buildings, machinery and equipment and of total fixed assets. Hence, the estimates of economic depreciation rates thus obtained measure how the value of capital assets changes over time for individual firms, instead of for individual classes of assets as studied in the traditional depreciation estimation. The traditional methodologies for measuring economic depreciation rates use market transaction data on asset resale or rental prices. A large number of studies [Hulten and Wykoff 1981, Oliner 1996, Fraumeni 1997], which were based on vintage asset prices, estimated the economic depreciation 9 rates for various classes of assets in different U.S. and Canadian industries. However, these approaches require the existence of thick resale or rental markets, which is lacking for most developing countries. Should these data become available, the traditional methodologies ought to be used to estimate the depreciation rates of capital assets in developing countries and validate the findings of high capital stock depreciation in some of these countries. For each country and wherever it is possible, I calculate the economic depreciation rate for total fixed assets in each firm, and also separately, for buildings, machinery and equipment. By the perpetual inventory method, the depreciation rate, which is assumed to be constant, can be implied from the investment series and the firm's estimates for the sale values of fixed assets at the beginning and end of the period that the investment series spans. In other words, the depreciation rate can be solved for from the following capital accumulation equation: K ti ⋅ (1 − δ ) T + T −1 ∑ {( I i t + s ,t − DI ti+ s ,t ) ⋅ (1 − δ ) T − s −1 } = K ti+T ,t , s =0 where K ti is the market value of fixed assets at the beginning of period t, I ti is the amount of new investment during period t, and DI ti is the selling price of assets sold during period t, all measured at the prices prevailing in period t , with the superscript i denoting firm i 6. The series K ti+ s ,t , I ti+ s ,t and DI ti+ s ,t are measured in constant (period t ) local currencies to exclude the effect of asset inflation on the asset value. Here, notice that the resale of fixed assets is considered as disinvestments. The major reason for firms to sell part of existing machinery and equipment, as reported in the survey, is normal replacement of old assets with new assets, and as a result, the selling price of old assets largely reflects their salvage values. Besides, firms have also sold their existing assets because of excess capacity, liquidity needs and no demand for 10 products. For the three Asian countries that are lacking in the data on the resale of fixed assets, the depreciation rate may be overestimated. Also in the measurement, the net book value of fixed assets recorded on the company account is used to approximate the value of K ti for the Asian countries. Table 2 summarizes the variables used in the measurement and their corresponding data series in the data sets. For the sample countries, all the investment series and sale values of fixed assets are recorded in current prices. The investment goods deflator is used and calculated from each country's nominal and constant domestic investment in capital goods, both in local currencies. The relevant data are obtained from the African Development Indicators [World Bank 2000a] and the World Development Indicators [World Bank 2000b]. For Ghana, Kenya and Zimbabwe, for which the data sets contain the current replacement values of fixed assets, an alternative aggregate investment goods deflator is constructed through the following two steps: i. For each individual firm in each country, a deflator is calculated as the changes in the replacement value of fixed assets between successive years. Mathematically, the realized asset inflation rate ( π ti ) can be obtained from (1 + π ti ) = ( ∑I v ≤t −1 ∑I i v ,t +1 i v ,t +1 ) /( ∑I i v ,t ) , where v ≤t −1 is the replacement value at the beginning of period t + 1 of fixed assets that v ≤ t −1 have been purchased and put in place at or before the beginning of period t . Further, ∑I v ≤ t −1 i v ,t +1 can be written as ( ∑I i v ,t +1 ) − I ti,t +1 , where in the estimation, ∑I i v ,t +1 is v ≤t v ≤t approximated by the replacement value of fixed assets at the beginning of period t + 1 . This approximation may bias downward the estimates of the economic depreciation rate, as some assets that may have exited from production during the previous period are still 11 assumed to be included in the stock of assets at the beginning of the current period and the asset price deflator is thus underestimated. ii. The aggregate investment goods deflator, denoted by (1 + π ta ) , is then obtained as the weighted sum of the deflators of individual firms by using each firm's current replacement value of fixed assets as weights to average out any firm-specific factor7 that may influence asset prices. In the capital accumulation equation, I ti+T ,t = I ti+T / T ∏ (1 + π a t + s −1 ), and s =1 K ti+T ,t = K ti+T / T ∏ (1 + π a t + s −1 ) , for T ≥ 1 , where (1 + π ta ) is the aggregate investment goods s =1 deflator that is obtained through the method just described. Here, to deflate the stock of capital at current prices to constant prices (that is, from K ti+T to K ti+T ,t ) requires the assumption that in i i i each period the asset inflation rate is constant across asset vintages, or ( p t +1,v − p t ,v ) / pt ,v = π ti , ∀v . {Insert Table 3 about Here} It deserves noting that the asset inflation rate, calculated as the rate of change in the replacement cost of the same cohort of assets, may be inaccurate and biased, given that most developing countries imports most of their capital equipment, and that exchange rate fluctuations may significantly modify the market value of capital. Table 3 presents the investment goods deflators calculated from using the replacement values of fixed assets between successive years (called the ‘weighted’ deflator and presented in Panel A) and those implied from each country’s national accounts (called the ‘SNA’ deflator and presented in Panel B). For Ghana, Kenya and Zimbabwe for which the weighted deflators are constructed, the ‘weighted’ deflator is generally 12 larger than the ‘SNA’ deflator, except that for Zimbabwe, the former is smaller than the latter for the year 1995. As an illustrative example, Table 4 describes the data and calculation formulas used in estimating the depreciation rate of fixed assets in a South Korean firm. {Insert Table 4 about Here} 4. Estimation Results Using the managers’ valuation of firms’ capital assets, I calculate the implied depreciation rates for each individual firm. The selected percentiles (10th, 25th, 50th, 75th, and 90th) along with the means and standard errors are presented in Table 5. The depreciation rates in Panel A of Table 5 are calculated using the investment goods deflators obtained from the countries’ system of national accounts. For Ghana, Kenya and Zimbabwe, alternative sets of deflators are calculated from the replacement costs of capital assets, and the resulting depreciation rates are shown in Panel B of the table. The depreciation rates in Table 5 are for machinery and equipment in Ghana and Kenya, and for fixed assets (including nonresidential structures, machinery and equipment) in the other sample countries. {Insert Table 5 about Here} As observed from Table 5, except for Indonesia, over 10% of the firms in the sample countries have negative depreciation rates. Other than reporting and measurement errors, this may come from the following sources. First, provided that the countries import most of their capital equipment from advanced industrial countries, currency depreciation (relative to the capital exporting countries’ currency) can cause the values of capital assets to rise and thus possibly lead to negative depreciation rates. The changes in the valuation of capital assets due to foreign exchange fluctuations could not be fully captured in either of the investment goods deflators calculated here. Second, the asset prices have been deflated to a common base using a common investment goods deflator for all firms in each country. Some firms with industryspecific assets may have had experienced much higher (than average) asset inflation. 13 Consequently, the market value of the same vintage of assets may not be on the same level as before even after being adjusted for general asset inflation8. The other extreme result from the estimation is that some estimates of the depreciation rate exceed 1, the maximum value allowed in theory. This implies that the economic value of capital goods declines immediately after they are installed; in other words, the investment spending occurring during the current period is less than the corresponding increase in the stock of capital at the end of the period. This corresponds to the concept proposed in Pritchett [1997] that the actual cost of investment is not equal to the value of capital created. Table 5 shows that for the four African countries, a large proportion of the firms have experienced much more rapid value decline in capital assets (machinery and equipments for Ghana and Kenya), at the rates much larger than the corresponding normal values. For instance, for over 75% of the firms in Cote d’Ivoire, the depreciation rate of total fixed assets exceeds 0.1, as compared to the rate of 0.07 usually assumed for the U.S. economy [Easterly and Rebelo 1993]. For machinery and equipment in Ghana, the depreciation rate exceeds 0.5 for half of the firms, as compared to the standard rate of 0.15 for machinery and 0.24 for transport equipment [PWT 5.6]. For Zimbabwe, while both the mean and the median are much higher than 0.07, the sample mean would be greater than 0.07 for more than 80% of the time if using the SNA deflators and for nearly 100% of the time if using the weighted deflators. The depreciation rates of capital in the sample of Kenyan firms are so dispersed that the sample could not give meaningful implications for population characteristics. High depreciation rates are also observed for the Asian countries. In Indonesia, the economic depreciation rates of fixed assets are over 0.4 in more than 90% of the firms. Similarly but to a much lesser extent, Philippines has about 75% of the firms having depreciation rates larger than 0.07 and about 50% larger than 0.17. In contrast, South Korea is the only Asian 14 country in the sample in which most of the firms have depreciation rates close to the standard value. {Insert Tables 6 and 7 about Here} As the percentile summary of individual firms’ depreciation rates treats firms of disparate sizes equally, I also calculate the sample average of depreciation rates for all firms combined for each country using the aggregated capital stock and investment series. Consistent with the findings at the individual firm level, Table 6 shows that at the aggregate level, the depreciation rates of fixed assets in the selected firms in the four African countries are much higher than the rates usually assumed in growth literature, while such high depreciation has been least severe in Kenya. For Ghana, the sample average rate of economic depreciation of machinery and equipment is 0.448 if the SNA deflators are used, exceeding the standard rate for machinery and equipment by at least 0.2. As compared, machinery and equipment in the Kenyan firms are estimated to depreciate at 0.158, which is within the normal range. The same situation holds for Cote d’Ivoire for the same type of assets. However, business constructions in Cote d’Ivoire depreciate, by estimation, at about 0.10, higher than the usually assumed rate of 0.035 for constructions [PWT 5.6]. This brings the overall depreciation rate of fixed assets in the country to an estimated value of 0.148. Also shown in the table, machinery and equipment and overall fixed assets in the Zimbabwean firms have higher depreciation rates, with the depreciation rate of fixed assets estimated to be at least 0.12 higher than the normal rate. For all sample countries, using the weighted deflators, which are lower in value than the corresponding SNA deflators, yield even higher depreciation rates. The Southeast Asian countries are also found to have anomalous capital depreciation rates at the aggregate level. While both Indonesia and Philippines have much larger depreciation rates for all sample firms combined, high depreciation has been far more severe in the former than in the latter countries. By contrast, for machinery and equipment in the manufacturing 15 industries of South Korea, the sample average rate of depreciation for the period 1996-1998 is 0.174, comparable to the standard values. High depreciation observed in the two Southeast Asian countries might be, by conjecture, partly due to the large amount of resale of fixed assets by a large proportion of firms in the sample during the measurement period9; however, the data on the resale of assets in the Asian countries are not available from the surveys. It should be pointed out that for both Philippines and South Korea, the economic depreciation rate is much smaller in the second measurement period 1997-1998 when the financial crisis hit the region. Such differences in depreciation rates between different time periods may be caused by the same factor having caused negative depreciation rates. Domestic currency devaluation, which occurred during the financial crisis, makes capital assets imported from advanced industrial countries or incorporating lots of imported parts appreciate in value, and consequently lowers the estimates of their rates of economic depreciation. {Insert Table 8 about Here} For comparison purposes, the depreciation rate is also directly calculated as the ratio of the depreciation expenses recorded in the company account to the value of total fixed assets at the beginning of the period for each country. The results are summarized and presented in Table 8. The results show that using the recorded depreciation expenses can yield ‘normal’ depreciation rate estimates for all the sample countries. In this sense, it provides additional evidence for Pritchett’s statement that the stock of capital obtained by way of CUDIE deviates from or exceeds the market value of capital assets in place in certain developing countries. 5. Possible Causes of High Depreciation in Developing Countries The results in the previous section suggest that larger-than-standard rates of physical capital depreciation may commonly exist in some developing countries. The same type of capital 16 may have a much larger depreciation rate in some countries than in others, because of undermainteance10 and extraordinary discard, the reasons for which are discussed below. Various related literatures have suggested many economic forces that may influence the level of capital maintenance. Tanzi and Davoodi [1997], using cross country data and regression analysis, find that the countries with widespread corruption are associated with higher public investment but lower expenditures on maintenance and operation. With the presence of noncompetitive and nontransparent bidding and contracting procedures, the corruption ‘premium’ may be much higher on capital-intensive expenditures, and as a consequence, labour-intensive activities, such as maintaining existing capital, are unattractive to the public officials. The low level of capital maintenance may be related to the expected future utilization rates of existing capital. As argued in Bitros [1976], the rational decision will ensure that the discounted value of expected returns from maintaining old equipment or structures must be at least equalized with maintenance expenditures thus incurred. Given that the profitability of capital maintenance must be increasing in the intensity of future capital utilization, the lower the expected rates of future capital utilization, the less is the expenditure on capital maintenance and hence the larger is the capital discard rate. Winston [1984] conducted a survey of capital utilization rates in selected industries for a sample of developing countries and found that capital was generally underutilized in those countries. If, however, capital underutilization and high costs of new capital goods relative to maintenance and repair costs exist simultaneously, as is often the case in the developing countries, it would be difficult to predict how the expenditures on maintenance, and thus the depreciation rates, would change on balance. The time preference rate used by the firms in developing countries may also be relevant to the country differences in depreciation rates. The theoretical findings in Becker and Mulligan [1997], supported with empirical evidence in their paper, suggest that a low level of wealth and uncertainty induce impatience or high time preference rate. An increase in the time preference 17 rate would result in a reduction in asset market value, which in turn implies a higher economic depreciation rate. It remains to be further explored how the investment behaviour and depreciation rate of each individual firm may depend on its discount rate. {Insert Table 9 about Here} Using the data collected from the World Bank surveys, Table 9 shows that high capital depreciation observed in the manufacturing industries of some developing countries may be a consequence of distortions due to government financing policies, such as special tax credits to corporate investment, or subsidies to investment loans. Table 9 reports and compares the depreciation rates between firms with government investment incentives and those without such incentives for Indonesia and South Korea, the only two countries for which the surveys collect relevant data on government-provided incentives. The depreciation rates are presented by industry sector. Within the same industry in South Korea, the firms receiving government incentives have higher depreciation rates than those without incentives. The overall depreciation rate is 0.195 for all the government-supported firms combined, as compared with the rate of 0.07 for the firms with no support. The incentive-induced differences in depreciation rate also vary by industry. For instance, for the automobile parts industry, the difference is as large as nearly 0.3, but much smaller for the chemicals and garments and textiles industries. Government incentives are likely to raise the relative cost of maintaining existing capital by causing the costs of new investment to decline, and hence result in the substitution of new capital for appropriate maintenance on old capital. As shown in Panel B of Table 9, for the electronics sector in Indonesia, investment incentives from the government causes a much higher depreciation rate (0.817 as compared to 0.343), whereas the rate differences for the other three industry sectors (food, chemicals, garments and textiles) are much less significant. The overall depreciation rate for all firms with support is 0.775, as compared to 0.712 for the firms with no support. 18 6. Implications of High Depreciation for TFP Growth Estimates and Capital Growth In this section, I use the Nehru and Dhareshwar [1993] data set on physical capital stock covering the period 1950-1990 to examine how the estimates of TFP growth should be revised for the developing countries in which high capital depreciation prevails. Before subsequent analysis, the Nehru and Dhareshwar capital stock series are reproduced for all the sample countries, using the depreciation rate of 0.04 assumed in that paper. Gross domestic fixed investment in the data set includes investment in equipment (including machinery and transportation equipment) and structures (including both residential and nonresidential construction). As a result, the depreciation rates of fixed assets in Tables 6 and 7 are weighted with the depreciation rate of residential structure, which is assumed to be 0.035 as in PWT 5.6, to obtain the aggregate depreciation rate of physical capital stock for each country. The respective weights for business fixed capital assets and residential structure are obtained from PWT 5.6, which reports on capital stock compositions. For the African countries, the SNA deflators are used to obtain the implied depreciation rates, which are more conservative as compared to those using the weighted deflators. The resulting estimates are presented in Table 10. {Insert Table 10 and Figures 1 about Here} The estimates of physical capital depreciation rates given in Table 10 are used to construct a new capital stock series for each of the seven countries. The time series of physical capital-output ratios, computed using the new capital stock series and the series constructed with the assumed rate of 0.04, are plotted and compared in Figure 1. Except for Kenya and Zimbabwe, the old ratios have apparent positive trends for the sample countries during the period 1950-1990. However, the ratios of the new capital stock series to output have much less or no significant trends for the countries with much higher implied depreciation rates. A higher 19 physical capital depreciation rate may lead to a lower growth rate of capital, which in turn will revise the TFP growth estimates obtained in previous studies. {Insert Table 11 about Here} The TFP growth rate is estimated for each of the seven countries using the two sets of capital stock series. In the estimation, a Cobb-Douglas production function is assumed, so that the TFP growth rate is estimated as the residual between output growth and the weighted sum of labour and capital growth. In Table 11, the TFP growth estimates in columns (7) and (9) are obtained by treating raw labour and human capital as one explanatory variable and separately as two variables, respectively. The growth rates in columns (4), (5), (6) and (8) are the trend estimates by fitting exponential curves to the time series of output, physical capital, labour and human capital, respectively, where human capital is measured by the average number of years of education also taken from the Nehru and Dhareshwar data set. In the calculations for column (9), the factor shares of physical capital, raw labour and human capital are assumed to be 0.4, 0.3 and 0.3, respectively, while for column (8) the share of labour is 0.6. Here, the values of the factor shares are chosen to be consistent with the choices in Pritchett [1997, 2000]. Except for Indonesia, the new capital stock series had been accumulating at lower rates, as compared to the old series. As a result, the resulting TFP growth estimates should be higher to various degrees for these countries. For instance, in the case of Ghana, when the depreciation rate changes from 0.04 to 0.17, the TFP growth estimates is revised from –0.0118 to –0.0017 if human capital is combined with raw labour, or from –0.0189 to –0.0087 if human capital is treated separately. With human capital and raw labour combined, a zero growth rate of TFP would require a depreciation rate of close to 0.25 for Ghana (not shown in Table 11). In this respect, some factors other than high depreciation (for example, capital underutilization and low capital productivity) should also contribute to the negative estimates of TFP growth observed in Pritchett [1997]. 20 {Insert Figure 2 about Here} One issue is worthy of further comments. As shown in the case of Indonesia, a higher depreciation rate does not necessarily imply a lower growth rate of capital. As a time-invariant depreciation rate is assumed and used throughout the paper to depreciate the value of capital investment geometrically, faster depreciation of fixed capital assets may be associated with higher volatility of capital stock growth. Figure 2 plots out the R-squares obtained in the exponential fit of capital stock series against the depreciation rate. In the figure, as the depreciation rate increases, the goodness of fit for all the countries decreases. This implies that the growth rate of physical capital stock is more volatile when capital depreciates at a higher rate. The relationship between capital depreciation rates and capital growth volatility also varies across countries. The goodness of exponential fit for the three Asian countries is relatively stable in response to the changes in the rate of capital depreciation, as compared with those for the four African countries. It can be simulated how capital accumulates under different assumptions of depreciation rate and investment series, a topic that is beyond the scope of this paper but should be explored in further studies of capital accumulation in developing countries. Using Ghana as an example, and for the depreciation rates of 0.04 and 0.172, Figure 2 also graphs the evolutions of capital stock against time and the associated exponential fits. 7. Concluding Remarks Using the firm level data sets on the resale values of capital assets and investment series in a group of countries in Africa, East Asia and Southeast Asia, this paper estimates the economic depreciation rates of physical capital stock for each individual firm as well as for all sample firms combined. In the estimation, all capital assets, including business buildings and machinery and equipment, have been deflated to a common basis, and where data are available, appropriate adjustments made for the resale of assets during the measurement periods. The results indicate 21 that capital may have been depreciating at comparatively higher rates in the developing countries, whereas the extent of high depreciation varies by country. This paper then reviews relevant literatures on the possible causes of capital undermaintenance in developing countries, and shows with empirical evidence that government-provided investment incentives induce high capital depreciation in South Korea, and in some of the manufacturing industries in Indonesia. This paper further calculates the TFP growth rates for all the sample countries, using the newly estimated depreciation rates and capital stock series. The revisions to the growth rate of capital stock necessarily lead to corresponding changes in the TFP growth estimates. Besides its growth effect, lowering the high depreciation rates of fixed capital stock can also significantly stabilize the process of capital accumulation and thus indirectly promote capital and output growth. To understand the underlying causes for high depreciation in developing countries, further research may fully develop a conceptual framework to explore the economic implications of various political-economy factors for capital accumulation. Relevant inquiries may include whether corruption, government and international financing policies may reduce the incentive to well maintain existing assets and thus result in faster depreciation. Besides, an independent and comprehensive industrial survey of capital stocks in developing countries is also needed for systematically validating and measuring the depreciation rates in the developing countries. NOTES: 1. Easterly and Rebelo [1993] use the depreciation rate of 7% uniformly for all countries and all periods, as compared to 0.04 in Nehru and Dhareshwar [1993]. Penn World Table 5.6 uses 15% for machinery, 24% for transport equipment, and 3.5% for constructions including both residential and nonresidential structures. 2. The aggregate capital stock data sets currently available for economic research are constructed by using the perpetual inventory method and the standard assumptions about the capital depreciation rates. 3. In the presence of inefficiency, as argued in Pritchett [1997], the accounting cost incurred during creating new capital may well exceed the economic cost, which is defined as, by Pritchett, the minimum cost of creating the same amount of capital given the optimal (or undistorted) market prices of investment goods. 4. As Leonard [1985] points out, there is no systematic financial account in the government to keep track of the accumulated depreciation on infrastructure capital. Also even though capital maintenance is investment-type expenditure in the sense that it yields returns over a much longer run than most ‘current’ expenditures, maintenance expenditure has long been treated as a current operating cost of the government. 22 5. Net book value, as defined in the survey, is the initial value or acquisition cost of fixed assets less accumulated depreciation charges. Here, it is considered as an approximate for the asset market value. 6. The capital depreciation rate estimates obtained through the above equation are de facto the assetsweighted averages of the depreciation rates during the time period under study. However, the capital depreciation rates, especially at the firm level, should vary in response to various factors such as corporate tax policies, and reallocation of physical capital assets across firms and sectors. 7. Such factors may include the corruption surcharge in corporate procurement of assets, which may differ across firms. 8. However, if firm-specific investment goods deflators are used for each individual firm, such deflators, which are calculated from the replacement values for the firm’s fixed assets and investment, could be heavily biased due to measurement errors and reporting errors. 9. Using the equipment level data from aerospace industry auctions, Ramey and Shapiro [2001] show that capital is sector-specific, and reallocation of sector-specific capital, combined with thinness of asset resale markets, results in substantial decline in market value. 10. Undermaintenance on public capital in particular is commonly observed for many developing countries [World Bank 1994]. 23 REFERENCES Bitros, G.C., 1976, A Statistical Theory of Expenditures in Capital Maintenance and Repair. Journal of Political Economy, 84(5), 917-936. Becker, G.S. and Mulligan, C.B., 1997, The Endogenous Determination of Time Preference. Quarterly Journal of Economics, 112(3), 729-753. Devarajan, S., Easterly, W. and Pack, H., 2003, Low Investment is not the Constraint on African Development. Economic Development and Cultural Change, 51(3), 547-571. Easterly, W., 1999, The Ghost of Financing Gap: Testing the Growth Model Used in the International Financial Institutions. Journal of Development Economics, 60(2), 423-438. Easterly, W. and Rebelo, S., 1993, Fiscal Policy and Economic Growth. Journal of Monetary Economics, 32(3), 417-458. Fraumeni, B.M., 1997, The Measurement of Depreciation in the U.S. National Income and Product Accounts. Survey of Current Business, 7-23. Hulten, C.R., 1990, The Measurement of Capital, in: E.R. Berndt and J.E. Triplett (eds) Fifty Years of Economic Measurement, Studies in Income and Wealth, (Chicago: Chicago University Press for the National Bureau of Economic Research), pp. 119-152. 24 Hulten, C.R., 1996, Infrastructure Capital and Economic Growth: How Well You Use It May Be More Important Than How Much You Have. NBER Working Paper, No. 5847. Hutlen, C.R. and Wykoff, F.C., 1981, The Estimation of Economic Depreciation Using Vintage Asset Prices. Journal of Econometrics, 15(3), 367-396. Jorgenson, D.W., 1989, Capital as Factor of Production, in: D.W. Jorgenson and R. Laudau (eds) Technology and Capital Formation, (Cambridge, Massachusetts: MIT Press), pp. 1-35. Jorgenson, D.W., 1996, Empirical Studies of Depreciation. Economic Inquiry, 34(1), 24-42. Leonard, H.B., 1985, Checks Unbalanced: The Quiet Side of Public Spending (New York: Basic Books). Nehru, V. and Dhareshwar, A., 1993, A New Database on Physical Capital Stock: Sources, Methodology and Results. Revista de Analisis Economico, 8(1), 37-59. OECD, 1993, Methods Used by OECD Countries to Measure Stocks of Fixed Capital, National Accounts: Sources and Methods No.2 (Paris: Organisation for Economic Co-Operation and Development). OECD, 2001, Measuring Capital: OECE Manual: Measurement of Capital Stocks, Consumption of Fixed Capital and Capital Services (Paris: Organisation for Economic Co-Operation and Development). 25 Oliner, S.D., 1996, New Evidence on the Retirement and Depreciation of Machine Tools. Economic Inquiry, 34, 57-77. Penn World Table (Mark 5.6), Centre for International Comparisons, University of Pennsylvania (available at: http://pwt.econ.upenn.edu/home.html). Pritchett, L., 1997, Mind Your P's and Q's: the Cost of Public Investment in Not the Value of Public Capital. World Bank Working Paper, No. 1660. Pritchett, L., 2000, The Tyranny of Concepts: CUDIE (Cumulated, Depreciated, Investment Effort) is Not Capital. Journal of Economic Growth, 5(4), 361-384. Ramey, V.A. and Shapiro, M.D., 2001, Displaced Capital: A Study of Aerospace Plant Closings. Journal of Political Economy, 109(5), 958-992. Tanzi, V. and Davoodi, H., 1997, Corruption, Public Investment, and Growth. IMF Working Paper, No. 97/139. Winston, G., 1984, The Utilization of Capital in Developing Countries: A Survey of Empirical Estimates. Prepared for Global and Conceptual Studies Branch, Division for Industrial Studies, United Nations Industrial Development Organization. World Bank, 1994, World Development Report 1994: Infrastructure for Development (Washington D.C.: Oxford University Press). 26 World Bank, 2000a, African Development Indicators CD-ROM (Washington D.C.: World Bank). World Bank, 2000b, World Development Indicators CD-ROM (Washington D.C.: World Bank). 27 Table 1. Data Description [1] [2] Country Cote d'Ivoire Ghana Kenya Zimbabwe Indonesia Philippines South Korea Period 1991-95 1992-93 1993-94 1993-95 1997-98 1996-98 1996-98 [3] [4] [5] [6] Total 229 212 215 213 562 541 863 Fixed Assets 61 . . 79 401 162 485 Buildings 47 . . . 389 170 434 ME 59 115 71 102 406 203 473 [7] Resale of Fixed Assets 18 . . 25 . . . [8] [9] Resale of Buildings 2 . . . . . . Resale of ME 15 4 3 29 . . . Column 3 is the number of firms in the data set, or the number of firms that responded to the World Bank surveys. Columns 4 through 6 are the numbers of the firms for which the data needed for measuring economic depreciation are available for the type of asset. Columns 7 through 9 are the number of firms that have sold assets during the measurement period. Table 2. Summary of Variables Country Kt Cote d’Ivoire Current market value Ghana Current market value Kenya Current market value Zimbabwe Current market value Indonesia Net book value South Korea Net book value Philippines Net book value It Nominal investment Nominal investment Nominal investment Nominal investment Nominal investment Nominal investment Nominal investment ∑I v ,t +1 v ≤t . Current replacement value Current replacement value Current replacement value DIt Resale price Resale price Resale price Resale price . . . . . . Table 3. Investment Goods Deflators Panel A. Deflators Calculated from System of National Accounts Cote d'Ivoire Ghana Kenya Zimbabwe 1.000 . . . 1990 0.983 . . . 1991 1.018 1.000 . . 1992 0.900 2.316 1.000 1.000 1993 1.734 . 1.180 1.210 1994 1.041 . . 1.293 1995 1996 1997 1998 Indonesia . 1.000 2.042 Philippines 1.000 1.045 1.119 South Korea 1.000 1.057 1.114 Panel B. Deflators Calculated from Assets Replacement Costs Ghana Kenya Zimbabwe Fixed ME ME ME Assets 1.000 . . . 1992 3.006 1.000 1.000 1.000 1993 . 1.751 1.473 1.777 1994 . . 1.183 1.173 1995 30 Table 4. Calculating the Implied Depreciation Rate of Fixed Assets for a South Korean Firm: An Illustration 596 Firm ID (in million won) Given: Investment [1] [2] 1996 1997 100 100 [3] 1998 20 [4] 1996 3600 Fixed Assets [5] 1997 3400 [6] 1998 2939 Investment Goods Deflator [7] [8] [9] 1996 1997 1998 1.000 1.057 1.114 Calculated: Investment - Deflated Value [1]' [2]' [3]' 1996 1997 1998 100 95 18 Fixed Assets - Deflated Value [4]' [5]' [6]' 1996 1997 1998 3600 3218 2637 Implied Rate of Depreciation [10] [11] [12] 1996-98 1996-97 1997-98 0.160 0.133 0.186 (a) The formulas used in calculations: [i]'=[i]/[7], for i = 1, 4; [i]'=[i]/[8], for i = 2, 5; [i]'=[i]/[9], for i = 3, 6; [10] = 1 - {[[2]'^2-4*[4]'*([3]'-[6]')]^0.5-[2]'}/(2*[4]'), which is the solution to the equation [6]'=(1-[10])^2*[4]'+(1-[10])*[2]'+[3]'; [11] is solved from the equation (1-[11])*[4]'+[2]'=[5]'; and [12] is the solution to (1-[12])*[5]'+ [3]'= [6]'. (b) 'Investment' occurs during the period indicated, while 'Fixed Assets' refers to the end-of-the-period value. 31 Table 5. Percentile Summary for the Depreciation Rates of Fixed Assets: Panel A. Use Deflators implied from SNA Cote d'Ivoire Ghana 1991-95 1992-93 0.2723 0.3437 Mean 0.0420 0.0507 Standard Error -0.0438 -0.3185 10th 0.1265 0.0624 25th 0.2594 0.5079 Median 0.3897 0.6680 75th 0.4578 0.8867 90th Kenya 1993-94 -0.1495 0.1492 -1.4568 -0.4236 0.1661 0.5256 0.8727 Zimbabwe 1993-95 0.1118 0.0482 -0.4377 -0.0548 0.2109 0.3826 0.5856 Panel B. Use Weighted Deflators Ghana Kenya Zimbabwe 1992-93 1993-94 1993-95 0.4943 0.2250 0.2221 Mean 0.0391 0.1006 0.0418 Standard Error -0.0159 -0.6565 -0.2501 10th 0.2775 0.0401 0.0704 25th 0.6208 0.4377 0.3141 Median 0.7442 0.6801 0.4595 75th 0.9127 0.9141 0.6166 90th For Ghana and Kenya, the depreciation rates are for machinery and equipment. Indonesia 1997-98 0.8408 0.0644 0.4278 0.5234 0.6142 0.9515 1.2044 Philippines 1996-98 0.2585 0.0383 -0.0161 0.0711 0.1659 0.3300 0.9587 South Korea 1996-98 0.0927 0.0201 -0.0628 0.0527 0.1186 0.2010 0.3452 Table 6. Depreciation Rates for the African Countries: Sample Weighted Averages Fixed Assets Buildings ME SNA Weighted SNA Weighted SNA Weighted Country Period Deflator Deflator Deflator Deflator Deflator Deflator 1991-95 0.148 . 0.100 . 0.183 . Cote d'Ivoire 1992-93 0.249 0.303 . . 0.448 0.575 Ghana 1993-94 0.123 0.236 . . 0.158 0.432 Kenya 1993-95 0.183 0.286 . . 0.266 0.300 Zimbabwe (a) The depreciation rates under 'SNA Deflator' are calculated by using the deflators implied from the country's national accounts, while those under 'Weighted Deflator' are calculated by using the deflators obtained from the replacement values of fixed assets between successive years. (b) In calculating the depreciation rates of fixed assets in Ghana and Kenya, the depreciation rate of buildings in Cote d'Ivoire is weighted with their respective rates for machinery and equipment. The relative market values of land And buildings and machinery and equipment (in the year of 1993 for Ghana and 1994 for Kenya) are used as weights in the calculation. 33 Table 7. Depreciation Rates for the Asian Countries: Sample Weighted Averages Fixed Assets Buildings Country 1996-98 1996-97 1997-98 1996-98 1996-97 . . 0.772 . . Indonesia 0.286 0.302 0.276 0.229 0.258 Philippines 0.116 0.217 0.024 0.062 0.144 South Korea 34 1997-98 0.755 0.210 -0.020 Machinery and Equipment 1996-98 1996-97 1997-98 . . 0.778 0.363 0.362 0.363 0.174 0.294 0.072 Table 8. Depreciation Rates: Sample Weighted Averages Using Depreciation Expenses Recorded on the Company Account Aggregate Depreciation Rate Country Period Assets . . . Cote d'Ivoire 1992-93 ME 0.076 Ghana 1993-94 ME 0.066 Kenya 1993-94 Fixed Assets 0.063 Zimbabwe 1994-95 Fixed Assets 0.050 1996-97 Fixed Assets 0.020 Indonesia 1997-98 Fixed Assets 0.010 1996-97 Fixed Assets 0.070 Philippines 1997-98 Fixed Assets 0.010 1996-97 Fixed Assets 0.100 South Korea 1997-98 Fixed Assets 0.090 Table 9. Capital Depreciation Rate and Government Incentives by Industry Sector: Panel A. South Korea (1996-98) Sector Electronics Auto Parts Chemicals Machinery Garments and Textiles Overall Financial Support No Financial Support Overall 0.284 (42) 0.204 (24) 0.135 (48) 0.107 (25) 0.154 (33) 0.195 (172) 0.111 (22) -0.095 (30) 0.091 (76) -0.046 (39) 0.129 (65) 0.07 (232) 0.195 (72) 0.021 (64) 0.115 (138) 0.012 (74) 0.133 (105) 0.118 (453) Panel B. Indonesia (1997-98) Incentives for No Investment Incentives Sector Overall 0.817 0.343 0.75 Electronics (22) (26) (48) 0.636 0.712 0.685 Food (28) (102) (130) 0.851 0.776 0.8307 Chemicals (39) (77) (116) 0.639 0.748 0.656 Garments and Textiles (21) (76) (97) 0.775 0.712 0.753 Overall (110) (281) (391) (a) The numbers in the parentheses are the number of firms. (b) 'Financial Support' and 'Incentives for Investment' are the words used in the surveys for South Korea and Indonesia, respectively. Table 10. Implied Depreciation Rates for Aggregate Physical Stock of Capital Country Period SNA Deflator Weighted Deflator 1991-95 0.102 . Cote d'Ivoire 1992-93 0.172 0.207 Ghana 1993-94 0.092 0.164 Kenya 1993-95 0.168 0.259 Zimbabwe 1997-98 0.607 . Indonesia 1996-99 0.230 . Philippines 1996-98 0.099 . South Korea (a) The depreciation rate of aggregate physical stock of capital is calculated as the weighted average of the depreciation rates of fixed assets reported in Tables 6 and 7 and that of residential construction. The weights are obtained from the Summer-Heston Penn World Table 5.6, and residential construction is assumed to depreciate at 0.035 for all sample countries; (b) For Ghana, I use Kenya's capital stock composition as weights, and for Indonesia, use Philippines' capital stock composition as weights, as the Penn World Table 5.6 does not report capital stock composition for Ghana and Indonesia. 37 Table 11. Estimates of TFP Growth Rates [1] [2] [3] Country Cote d'Ivoire Period 1960-90 Ghana 1951-90 Kenya 1951-90 Zimbabwe 1955-90 Indonesia 1951-90 Philippines 1951-90 South Korea 1954-90 Physical Capital Depreciation Rate 0.0400 0.1016 0.0400 0.1722 0.0400 0.0917 0.0400 0.1676 0.0400 0.6072 0.0400 0.2300 0.0400 0.0987 [4] [5] [6] Output Growth Rate 0.0537 0.0537 0.0178 0.0178 0.0518 0.0518 0.0434 0.0434 0.0593 0.0593 0.0472 0.0472 0.0803 0.0803 Physical Capital Growth Rate 0.0781 0.0625 0.0381 0.0127 0.0335 0.0226 0.0359 0.0145 0.0710 0.0721 0.0655 0.0500 0.1184 0.1142 Labor Growth Rate 0.0374 0.0374 0.0240 0.0240 0.0339 0.0339 0.0341 0.0341 0.0240 0.0240 0.0302 0.0302 0.0229 0.0229 [7] TFP Growth Rate w/o human capital 0.0000 0.0063 -0.0118 -0.0017 0.0181 0.0224 0.0086 0.0171 0.0165 0.0161 0.0029 0.0091 0.0192 0.0209 [8] Human Capital Growth Rate 0.0968 0.0968 0.0475 0.0475 0.0405 0.0405 0.0247 0.0247 0.0376 0.0376 0.0165 0.0165 0.0377 0.0377 [9] TFP Growth Rate w/ human capital -0.0178 -0.0116 -0.0189 -0.0087 0.0161 0.0204 0.0114 0.0200 0.0124 0.0120 0.0070 0.0132 0.0148 0.0164 (a) The physical capital depreciation rate of 0.04 is used in Nehru and Dhareshwar [1993] in constructing physical capital stock series. The implied depreciation rates are taken from Table 10. (b) The calculations of the 'TFP growth rate w/o human capital' assume the output share of physical capital to be equal to 0.4, and the output share of labor 0.6, while the calculations of the 'TFP growth rate w/ human capital' assume 0.3 for the output share of human capital and 0.3 for raw labor. Figure 1. Capital-Output Ratios Gh a n a 19 5 1- 9 0 C o t e d ' I v o i r e 19 6 1- 9 0 K/ Y K/ Y 3. 00 3. 00 2. 50 2. 50 0.040 2. 00 0.040 2. 00 1. 50 1. 50 0.102 1. 00 0.172 1. 00 0. 50 0. 50 0. 00 0. 00 1951 1955 1959 1963 1967 1971 1975 1979 1983 1987 1960 1963 1966 1969 1972 1975 1978 1981 1984 1987 1990 K e n y a 19 5 1- 9 0 Z i m b a b we 19 5 5 - 9 0 K/ Y K/ Y 5. 00 8. 00 7. 00 4. 00 0.040 6. 00 5. 00 0.040 4. 00 3. 00 3. 00 2. 00 0.092 2. 00 0.168 1. 00 1. 00 0. 00 0. 00 1950 1954 1958 1962 1966 1970 1974 1978 1982 1986 1990 1954 1958 1962 1966 1970 1974 1978 1982 1986 1990 P h i l i p p i n e s 19 5 1- 9 0 I n d o n e si a 19 5 1- 9 0 K/ Y K/ Y 2. 50 3. 50 3. 00 2. 00 2. 50 1. 50 0.040 2. 00 0.040 1. 50 1. 00 0.607 0. 50 1. 00 0.23 0. 50 0. 00 0. 00 1950 1954 1958 1962 1966 1970 1974 1978 1982 1986 1990 S o u t h K o r e a 19 5 4 - 9 0 K/ Y 2. 50 2. 00 0.040 1. 50 1. 00 0.099 0. 50 0. 00 1953 1957 1961 1965 1969 1973 1977 1981 1985 1989 1950 1954 1958 1962 1966 1970 1974 1978 1982 1986 1990 Figure 2. Depreciation Rate and Capital Stock Growth Volatility R - Squa r e f r om E x pone nt i a l Fi t D ep r eciat io n R at e and Exp o nent i al F i t o f C ap it al St o ck Ser ies C a pi t a l S t oc k C ap it al St o ck Evo lut io n and Exp o nent ial F it Ghana 19 50 - 19 9 0 1.20 1.00 Expon. R2 =0.8882 Korea Philippines 0.80 Indonesia 0.04 0.60 Cot e d'Ivoir e 0.40 0.20 Kenya Zimbabwe Ghana 0.00 P hy s i c a l C a pi t a l D e pr e c i a t i on R a t e 0.172 Expon. R2 =0.3568