TOPIC 2 The Supply Side of the Economy Goals of Lecture 2 • Introduce the supply side of the macro economy. • Discuss how countries grow and why some countries grow faster than others. • Discuss labor productivity o What does it mean? o How does it respond coming out of recessions? • Determine how wages are set in an economy. Determine why people work. • Understand where unemployment comes from. 2 The Production Function • GDP (Y) is produced with capital (K, price-weighted) and labor (N, hours): Y = A F(K,N) • Sometimes, I will modify the production function such that: Y = A F(K,N, other inputs) – where other inputs include energy/oil! • Realistic Example is a Cobb Douglas function for F(.): Y = A K.3 N.7 A is Total Factor Productivity (TFP), an index of efficiency (technology) MUST READ: NOTES 3 (my text posted on the teaching page) on the aggregate production function 3 Measurement • Y is GDP (measured in dollars). As noted above, we want to measure Y in “real” dollars.<<you should know what this means from Notes 1 of the text>>. • For our Cobb Douglas production function (previous slide), N and K are both measured in dollars. – N often is measured in total wage bill – K often is measured as the replacement cost of capital • However, in practice, N can be measured in different ways (hours worked, number of workers). – Wage bill is the preferred method (takes into account “skill” differentials). – However, we will often talk about standard of livings which is income per capita (Y/N ; where Y is income and N is some population measure). 4 Features of the Aggregate Production Function Define MPN = Marginal Product of Labor = dY/dN Define MPK = Marginal Product of Capital = dY/dK Math Note: You should be comfortable taking these simple partial derivatives– if you are not, practice this for the quizzes and exams. Diminishing Marginal Products From Cobb-Douglas: MPN = .7 A (K/N).3 = .7 (Y/N) Fixing A and K, MPN falls when N increases MPK = .3 A (N/K).7 = .3 (Y/K) Fixing A and N, MPK falls when K increases Complementarity Across Inputs Increasing A or K, increases MPN Increasing A or N, increases MPK 5 Two Measures of Productivity • Labor Productivity = Y/N = A (K/N).3 Driven by A and K/N (usually reported in press) • Total Factor Productivity (TFP) = A = Y/F(K,N) • Basically TFP is a ‘catch-all’ for anything that affects output other than K and N. – – – – – – – – Work week of labor and capital Quality of labor and capital Regulation Infrastructure Competition Specialization Innovation (including innovation in management practices) Changes in “discrimination” or “culture” • Some components of TFP tends to be pro-cyclical • (Definition of Pro-cyclical: Variable increases when Y is high, decreases when Y is low) 6 Sub-Section A Economic Growth Growth Accounting Y = A K.3 N .7 (our production function) %ΔY = %ΔA + .3%ΔK + .7%ΔN Output, in a country grows from: Growth in TFP (see entrepreneurial ability, education, roads, technology, etc.) Growth in Capital (machines, equipment, plants) Growth in Hours (workforce, population, labor participation, etc). Perhaps, we care about growth in Y/pop or Y/N (per capita output). %Δ(Y/pop) = %ΔA + .3%Δ(K/pop) + .7%Δ(N/pop) or %Δ(Y/N) = %ΔA + .3%Δ(K/N) 8 Productivity During Recession Y/N evolves by: Y falling (holding N constant) decreases Y/N N falling (holding Y constant) increases Y/N In recessions, both Y and N fall. The question of interest: Does Y or N fall more during a recession? 9 Output Per Worker (All Sectors): 1970Q1 – 2012Q2 10 Summary During recent recessions: N falls more than Y Y/N (a measure of productivity) actually increases We are producing more stuff – with less workers – during the recession! Note: The fact that productivity increases during recent recoveries is directly linked to the fact that recent recoveries have been “jobless” (discussed in lecture 1). The economy recovers but employment lags. Why are there jobless recoveries? 11 The Role of Investment and Growth Does a one time increase in investment today increase Y/N today? YES! Does a one time increase in investment today cause a sustained increase in Y/N into the future? No! Back of our mind equations: S = I + NX (From the first lecture). Notice the link between saving and investment. K(t+1) = (1-δ) K(t) + I(t) or ΔK(t, t+1) = I(t) - δ K(t) Definition of Capital Stock Evolution All else equal (i.e. holding N constant), increasing I causes K tomorrow to increase causing K/N tomorrow to increase (i.e. Y/N tomorrow increases). 12 Time Path of Capital Stock: One Time Increase in I K No investment No investment t+1 time Suppose there is a one time increase in investment at time t (perhaps due to an investment tax credit). Suppose no investment either prior to or after the tax credit. 13 Can Higher Investment Lead to Infinite Growth? Does a sustained increase in investment increase Y/N today? YES! Does a sustained increase in investment cause a sustained increase in Y/N? No! Suppose I is fixed at a high level and that K initially is sufficiently small. K grows if I > δ K: But, notice that δK is also growing each period. (Summary: To start, higher I will lead to higher K and Y/N will increase). Eventually, however, I will converge towards δK More and more of the investment is going to replace outdated capital and the capital stock will grow by smaller and smaller rates. The increase in Y/N will converge back to zero. Summary: High levels of investment will increase the capital stock and output, but both K and Y will eventually converge to a fixed level. 14 Time Path of K: Permanent Increase in I K The new level of investment has successively less effect due to growing depreciation of the capital stock. No investment t+1 time Suppose there is a permanent increase in investment at time t. Suppose no investment prior to t. In all periods after t, the level of investment remains fixed at the level in t. 15 Can Higher Investment Growth Cause Infinite Growth? If a one time increase in I gives an increase in Y, why not continuously raise I to higher and higher amounts??? Answer: Diminishing MPK!!! MPK = .3 A (N/K) .7; As K increases, MPK falls. As K goes to infinity, MPK goes to zero (Y stops increasing). Suppose, we keep rising I (each year), K will increase by the amount of I (after controlling for depreciation), but Y will increase by continuously smaller and smaller amounts. Remember Y = C + I + G + NX. I/Y (investment rate) is bounded by 1 (if you invest all your output). This caps the increase in I. I cannot grow forever! Continuously increasing I will NOT lead to sustained economic growth. NOTE: Investment decisions are NOT made in the dark (i.e. something must drive firm investment!) 16 What Causes Sustained Growth ? Sustained Increases in the growth of A are the only thing that can cause a sustained growth in Y/N. Empirically, when a country exhibits faster Y/N growth ….. 33% typically comes from growth in K/N 67% typically comes from growth in A (where N = employment (not hours) - limited data). 17 Growth Across Countries Most developed economies grow at the same rate that the “technological frontier” grows. Some helpful definitions: Convergence – countries inside of the technological frontier move towards the technological frontier. Divergence – countries inside of the technological frontier grow at a rate less than the technological frontier. 18 Distribution of World GDP in 2011 (WorldBank, $) 19 Distribution of World GDP in 2009 (IMF, $) Top 10 Median Bottom 10 Qatar 88,559 Ecuador 7,776 Togo 858 Luxembourg 81,383 China 7,519 Malawi 827 Singapore 56,522 Albania 7,453 Sierra Leone 807 Norway 52,013 El Salvador 7,430 Niger 755 Brunei 48,892 Tonga 7,275 Cent. Afric. Repub. 745 UAE 48,821 Guyana 6,964 Eritrea 681 U.S. 47,284 Namibia 6,953 Zimbabwe 434 Hong Kong 45,736 Algeria 6,950 Burundi 411 Switzerland 41,663 Turkmenistan 6,785 Liberia 392 Netherlands 40,765 Ukraine 6,712 Congo 328 20 Some Data: Distribution of World GDP in 2000 From Barro, 2003 – includes 147 countries. Horizontal axis is a log scale. All data are in 1995 U.S. dollars. 21 Some Data: Distribution of World GDP in 1960 From Barro, 2003 – includes 113 countries. Horizontal axis is a log scale. All data are in 1995 U.S. dollars. 22 Growth Rate of GDP Per Capita: 1960 - 2000 From Barro, 2003 – includes 111 countries. 23 Relative Growth Rate of GDP Per Capita: 1960 - 1988 U.S. is anchored at 1 in both years. Countries above the line have made gains relative to U.S. 24 Convergence of Income Across U.S. States: 1940 - 1980 Historical Trends in Convergence Unadjusted 1940-1960 1 MS .8 ARAL ND SD OK KY NC GA NM TN LA SC KS NE TX .6 WV UT MOCO IA MNWI ID VA AZ IN WY FL NHOR VT MT ME WA OH PA MI IL .4 MD CA NV MA NJ NY CT RI .2 DE 2000 4000 6000 8000 Per Capita Income 1940 Fitted values 10000 12000 gr_ipc_40_60 25 Convergence of Income Across U.S. States: 1980 - 2000 Recent Trends in Convergence Unadjusted 1980-2000 .5 MA NH CT NC GA NJ .4 VT SCNDSD TN ME AL KY MS MO IN .3 AR UTID WV .2 RI NE NM IA AZ MN VA PA FL TX MI WI OH KSOR NY CO WAIL DE CA LA MT MD NV OK .1 WY 15000 20000 Per Capita Income 1980 Fitted values 25000 gr_ipc_80_00 26 Bonus Section New Research Project: “The Allocation of Talent and Economic Growth” (Trying to Shed Light on the Black Box of TFP Growth) Measuring TFP (A) The way TFP (A) is usually measured is via a statistical decomposition (referred to as the “Solow Residual”). Remember our assumed production function: • Y = AK.3N.7 Math Note: We are going to transform the production function to make it a little easier to work with (you should get comfortable with this) by taking the logs: ln(Y) = ln(A) + α0ln(K) + α1ln(N) (where α0 = 1 – α1 ≈ 0.3) (1) • Given that we measure Y, K and N in the data, we can estimate (1) using standard regression techniques. • ln(A) is the constant from the regression. This is our standard TFP measure. 28 Measuring TFP Because A (TFP) is a catch-all term for anything that affects production, the assumed production function does not impose any structure on how to measure the components of TFP. Economists are very good at measuring the extent to which TFP changes over time within a country. It is much harder to measure “why” TFP has changed over time. Economists try to measure this by using detailed firm-level and household-level data to measure production and wages. 29 Our Project Question 1: How much of the observed TFP growth in the U.S. since 1960 is due to better labor market outcomes (including human capital formation) for blacks and women? o economic growth! A better allocation of resources leads to higher o There have been HUGE changes in the allocation of women and blacks in the labor market since 1960. Question 2: How much of the convergence of the U.S. south to the U.S. north is due to a 30 decline in discrimination of the south? Occupational Sorting Over Time: An Overview • Fraction of group (white men, white women, black men, black women) aged 25-55 working in the following occupations: Executives, Mgmt, Architects, Engineers, Math/Computer Science, Natural Scientists, Doctors, and Lawyers. 1960 White Men White Women Black Men Black Women Data: 2006-2008 21.2% 23.5% 3.0 (7.3) 17.4 (21.0) 2.8 14.6 1.0 (2.1) 13.0 (15.2) U.S. Census and American Community Survey Occupational Sorting Over Time: An Overview • Where were the other groups working in 1960? • 53% of working white women worked in Nursing, Teaching, Sales, Secretarial and Office Assistances, and Food Prep/Service. o • 55% of working black men worked as Freight/Stock Handlers, Motor Vehicle Operators, Machine Operators, Janitorial Services, and Personal Services. o • The comparable number for white men was 14% (mostly sales) The comparable number for white men was 19% 47% of working black women worked in Household Services, Personal Services, and Food Prep/Services. o The comparable number for white men was 2% Wage Gaps Over Time: An Overview • Log difference in annual earnings of full time workers, conditional on experience, hours and occupation controls (relative to White Men) 1960 1980 2008 White Women -0.56 -0.47 -0.26 Black Men -0.37 -0.21 -0.16 Black Women -0.82 -0.47 -0.31 Findings Macro Implications: o 15% − 20% of total wage growth in the U.S. between 1960 and 2008 was due to declining frictions for white women, black women, and black men. (Shines some light into the black box of TFP growth) o Other interesting results: - Wage growth in the 1970s and the 2000s would have been negative absent the labor market improvements for blacks and women. - About 40% of the convergence of the south to the northeast between 1960 and 1980 is due to declining labor market frictions. - Not much remaining room for growth from this mechanism. Sub-Section B The Labor Market Labor Market: Firm Profit Decisions • In a competitive market, a firm can sell as much Y as it wants at the going price p, and can hire as much N as it wants at the going wage w. • Facing w and p, a profit maximizing firm will hire N to the point were MPN = w/p (the benefit from an additional worker (in terms of additional output) must equal the cost which they are paid). <<This is straight from micro>> • With Cobb-Douglas: MPN = .7 Y/N = .7 A (K/N).3 • If firms maximize profits: w/p = .7 Y/N = .7 A (K/N).3 • If MPN > w/p then the firm can increase profits by increasing N. • If MPN < w/p then the firm can increase profits by decreasing N. Reading: Notes 4 from the supplemental notes 36 The Labor Demand Curve real wage w/p * MPN = Nd N* N 37 Notes on the Labor Demand Curve • Nd slopes downward (Nd = MPN = .7 A * (K/N).3) • Nd rises with A and K (assumed complementarity across inputs) • Assumption: Y is not Fixed! Firms optimally choose N, K, Y and (to some extent) A to maximize profits. • Caveat: Who says that there is a demand for more Y? – Need to look at the demand side of economy (introduced last -discussed in depth throughout the course). 38 The Other 1/2 of the Labor Market: Labor Supply • Labor Supply (Ns) Results from Individual Optimization Decisions • Households compare benefits of working (additional lifetime resources) with cost of working (forgone leisure) • Factors Affecting Labor Supply – – – – – – The Real Wage (w/p) The Household’s Present Value of Lifetime Resources (PVLR) The Marginal Tax Rate on Labor Income (tn) The Marginal Tax Rate on Consumption (tc) Value of Leisure (reservation wage) - non- ‘work’ status (VL) The Working Age Population (pop) 39 The Labor Supply Curve Ns(PVLR, tc, tn, pop, VL) w/p N 40 Labor Supply Notes (Most Derived From Scratch in Lecture) • In terms of ‘wages and earnings’, there is both an income and substitution effect - we will look at them separately – BUT in the real world, they often occur jointly!!!! • The Real Wage - HOLDING PVLR fixed: A higher w/p encourages individuals to substitute away from leisure and toward work (leisure becomes more expensive). This is a substitution effect. <<This is why the labor supply curve slopes upwards!!>> – Estimating this substitution effect is difficult since PVLR is not easily held constant. Estimates range from 0 - 2% (For a 1% increase in after-tax w/p holding PVLR fixed, labor supply either increases by 0% or 2%). Very Wide Range – little consensus. • PVLR = initial wealth + present discounted value of earnings – A higher PVLR induces individuals to work less (lower Ns) for a given after-tax wage, allowing them to enjoy more leisure (If leisure is preferred to work – as I get richer, I can afford to work less). – PVLR is net of taxes and non-work governmental transfers and inclusive of all other transfers. 41 Labor Supply Notes • Marginal tax rate on labor income - Should have same substitution effect as the before tax real wage. Studies of the 1986 U.S. Tax Reform found that only high-earning married women worked more in response to lower marginal income tax rates. • Marginal tax rate on consumption - see above • Value of Leisure - If leisure/no-work becomes more/less attractive, households will less/more (reservation wage). (Welfare programs, child care, etc.). • Working Age Population: Usually defined as 16-64. (Includes changes in Labor Force Participation Rates) Reading: #29 42 Recap on Labor Supply • Substitution Effect: – For a given PVLR, a higher after tax wage increases NS. (This is why Labor Supply Curve Slopes Upward) • Income Effect – For a given after-tax wage, higher PVLR decreases Ns. • Evidence: – Weak Consensus is that, with equal (%) increase in PVLR and the after-tax wage, Ns falls (income effect dominates). 43 Temporary Increase in A Ns(PVLR, tc, tn, pop, VL) w/p w/p * N d(A,K) N* N 44 Permanent Increase in A Ns(PVLR, tc, tn, pop, VL) w/p w/p * N d(A,K) N* N 45 Can Technological Progress Destroy jobs? Facts: A, N, w/p are trending up over time. N/pop is trending down (except in U.S. since 1980). Higher A countries have higher w/p and lower N/pop. Implications: Adjusting for pop, higher A goes with lower N. Higher A reduces Nd and destroys jobs? - NO! Labor Demand Increases. Higher A increases PVLR and reduces Ns - The Effect on Labor Supply is to fall. 46 Permanent Increase in Population Ns(PVLR, tc, tn, pop, VL) w/p w/p * N d(A,K) N* N 47 Population and Jobs More People = More Jobs 1990 Employment (000s) 1000000 100000 10000 1000 100 100 1000 10000 100000 1000000 1990 Working-Age Population (000s) 48 Temporary Increase in Taxes (tc or tn) Ns(PVLR, tc, tn, pop, VL) w/p w/p * N d(A,K) N* N 49 Permanent Increase in Taxes (tc or tn) Ns(PVLR, tc, tn, pop, VL) w/p w/p * N d(A,K) N* N 50 Labor Market Equilibrium (in long run!) • We define Long Run Equilibrium in macroeconomics as occurring when the labor market clears. • By definition, long run macro equilibrium exists when N = N*. • At N*, labor demand = labor supply. So, by definition, all workers who want a job (the suppliers) are able to find a firm looking for a worker (the demanders). • • • Implies that cyclical unemployment = zero at N*. Long run equilibrium is characterized by zero cyclical unemployment! It is an equilibrium in that there is no incentive for real wages to change at N* • Real wages (w/p) has two components: nominal wages (w) and the price level (p). • Note: • Y* is the long run equilibrium level of output (output where labor market is in equilibrium) Y* (by definition) = A K.3(N*).7 51 Our First Aggregate Supply Curve…. • Suppose prices (p) increase. What happens in the labor market? • • • In terms of equilibrium, nothing happens! Increasing prices have no effect on labor demand (A and K do not change). Increasing prices have no effect on labor supply (taxes, population, etc. do not change). • You may ask “Doesn’t PVLR change when prices increase???” No! • • • As long as nominal wages adjust, real wages will be unchanged when p increases. The % change in prices will be match exactly by the % change in nominal wages – real wages will not change (so PVLR will not change). No effect on labor supply. • Key: Because real wages will not change, changes in prices will have NO effect on the labor market (i.e., it will have no effect on N*). • Conclusion: Changing prices will have NO effect on Y* (since N* is constant). 52 Our First Aggregate Supply Curve…… LRAS – Long Run Aggregate Supply Curve p Y* Y • If labor market clears, changes in prices will lead to equal changes in nominal wages. As a result, there will be no change in N* and hence, no change in Y*. • Leads to a vertical LRAS curve. Prices do not affect production in the long run! 53 What Shifts Y*? (the LRAS) • Anything that affects the labor market will affect Y*! • If N* increases, Y* will shift to the right. • If N* decreases, Y* will shift to the left. • Summary: Y* will shift right if: – – – – – A increases K increases population increases labor income taxes fall (and income effect is small relative to substitution effect) labor income taxes rise (and income effect is large relative to substitution effect) Note: The long run aggregate supply curve (LRAS) is NOT the labor supply curve. We have lots of different markets in this class. There will be lots of different supply and demand curves. You need to keep track of them! 54 Things to Remember! • The demand side of the economy is NOT important for determining Y*! – All we need to know is A, K and N and we know Y*! – The demand side of the economy is not important for economic growth! – Key: If I ever ask you about what determines Y* (i.e., output/income/expenditure in the long run), you should think about A, K and the labor market. • • As a rule, K will be fixed unless I tell you otherwise (for simplicity, you will see why soon). Why do we care about the demand side of the economy? – – – In the long run, prices will be determined by demand. Also, LRAS is dependent on labor market being in equilibrium. In the short run, labor market need not be in equilibrium. Demand will determine output in the SHORT RUN! 55 Summary…. • In the long run – when labor markets clear. – Supply side of economy (labor market, K, A, other inputs like oil) determines output. – Demand side of economy (C+I+G+NX) will determine prices. • In the short run – when labor markets do not clear: – Demand and Supply jointly determine prices and output (think of the simple examples I gave graphically in the lecture for topic 1). – Three outstanding issues (we will get to them soon): • • • When is the labor market NOT in equilibrium? What does the supply curve look like when labor market doesn’t clear? What determines demand? 56 When are Labor Markets in Disequilibrium? • Labor market is in disequilibrium when labor demand is not equal to labor supply. • Any time labor demand = labor supply, there is no cyclical unemployment (by definition)! • Nominal wages do not adjust to clear the labor market – We refer to this as ‘sticky’ wages. – Because of wage contracts (and uncertainty), nominal wages do not always adjust immediately. – Need a model for short-run disequilibrium --- we will do that in Topic 6. 57 Cyclical Unemployment in Labor Markets • When do we get cyclical unemployment in our models? • Cyclical unemployment occurs when there are no jobs available (labor demand) for those with the skills and the desire to work (labor supply) at current wages. • Cyclical unemployment occurs only in disequilibrium! (when desired labor demand < desired labor supply - at given wages) Ns w’/p’ a b Unemployment N(1) N(0) Nd 58 What Have We Learned So Far? • There are microeconomic fundamentals to the supply side of the economy – – Capital accumulation, Labor and TFP are important for production AND Growth!!! • Some countries grow faster than others because they have rapid growth in TFP or K/N. • Only growth in TFP can lead to sustained growth in Y/N • How Labor Markets Work - The Role of Taxes, Technological Progress, Capital Accumulation, And Demographics on Wages and Employment. • Demand is not important for determining long run output (i.e., income, standard of livings, etc.). Supply (production) is the only thing that determines output in the long run! 59 Exploiting Within-U.S. Variation To Learn About Business Cycle Effects of Labor Markets My Recent Research on Housing/Manufacturing Two new papers with Kerwin Charles (Harris School) and Matt Notowidigdo (Booth). Exploit regional patterns in: o Manufacturing declines during 2000s (predicted by initial share of manufacturing in metropolitan area in year 2000). o Housing booms during 2000s (predicted by discrete changes in housing prices in metropolitan area during early 2000s). Analyze effects of changes on overall employment rates, wages, employment by sector, migration, human capital attainment, etc. Intuition of the Model: Labor Supply and Labor Demand Labor Supply Wages (W/P)1 (W/P)2 Labor Demand N2 N1 N Predicted Manufacturing Change vs. Change in Non-Employment, Non College Men 2000-2007 Bigger Manufacturing Decline Predicted Manufacturing Change vs. Change in Non-Employment, Non College Men 2000-2007 Increase in Non-Employment Bigger Manufacturing Decline Predicted Housing Demand Change vs. Change in Non-Employment, Non College Men 2000-2007 Bigger Housing Demand Shock Counterfactuals From Our Paper Estimated Effect of Manufacturing Decline on NonEmployment 0.080 0.070 0.060 0.050 0.040 0.030 0.020 0.010 0.000 -0.010 -0.020 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 Estimated Effect of Manufacturing Decline on NonEmployment 0.080 ~42% Explained 0.070 0.060 0.050 0.040 0.030 0.020 0.010 0.000 -0.010 -0.020 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 Estimated Effect of Housing Cycle on Non-Employment 0.080 0.070 0.060 0.050 0.040 0.030 Manufacturing Decline 0.020 0.010 0.000 -0.010 Housing Cycle (Construction and Other) -0.020 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 The Housing Boom Masked The Manufacturing Decline in 2000s 0.080 0.070 Data 0.060 0.050 0.040 0.030 Manufacturing 0.020 0.010 Housing + Manufacturing 0.000 -0.010 -0.020 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 The Housing Boom Masked The Manufacturing Decline in 2000s 0.080 0.070 Data 0.060 34% During Recession 0.050 0.040 0.030 Manufacturing 0.020 0.010 Housing + Manufacturing 0.000 -0.010 -0.020 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011