Macroeconomics of the Labor Market
Transcrição
Macroeconomics of the Labor Market
Macroeconomics of the Labor Market By Christian Merkl CES-Lecture 2: The Search and Matching Model and the Business Cycle Munich, August 2013 Labor Market Flows The Simplest Model Exogenous job destruction Employed Unemployed Matching function For matches: bargaining Vacancy posting Firms 2 Lehrstuhl für VWL Makroökonomik Strengths of Search and Matching • Elegance • Efficiency (under certain conditions) twin brother of RBC • Consistent dynamic framework • Model of labor market flows • Weaknesses? More on this issue later 3 Lehrstuhl für VWL Makroökonomik The Matching Function • Assume the following matching function, which is increasing in both arguments, concave and homogenous of degree 1 • Typically the matching function is specified as a Cobb-Douglas function (everything will be written in discrete time) • Microfoundations? 4 Lehrstuhl für VWL Makroökonomik Labor Market Tightness • denotes the labor market tightness • By using the homogeneity of the function, we can rewrite the rate at which vacant jobs become filled as • Trading externalities! 5 Lehrstuhl für VWL Makroökonomik Employment Dynamics • Let’s assume that there is a constant and exogenous job separation rate . • Workers’ job finding rate: • In equilibrium the number of workers who become unemployed must be equal to the number of workers who find a new job. • Employment to unemployment flows: • Unemployment to employment flows: • Employment dynamics equation: • Steady state employment: 6 Lehrstuhl für VWL Makroökonomik Sequence of Decisions 1. The firm has to post a vacancy. 2. The unemployed worker has to search. 3. The two parties have to meet and to make a match. 4. Since the search process was expensive, a job match yields a rent which is shared according to a bargaining rule. 7 Lehrstuhl für VWL Makroökonomik Job Creation 1: Present Value of a Vacant Firm • Present value of a vacant firm: • Present discounted value: minus vacancy posting costs plus future expected present value. • Free entry condition: Firms will post vacancies until the value of V is driven to 0. • Thus: 8 Lehrstuhl für VWL Makroökonomik Job Creation 2: Present Value of a Matched Firm • Present value of a matched firm J: • The return for the firm is equal to the goods price minus the wage plus the future value of the match. • Job creation condition: 9 Lehrstuhl für VWL Makroökonomik Workers’ Present Value • Present value of an unemployed worker: • Present value of an employed worker: 10 Lehrstuhl für VWL Makroökonomik Wage Determination • Nash bargaining solution: • Thus: • In terms of the wage: 11 Lehrstuhl für VWL Makroökonomik Equilibrium • Three steady steate equations (in continuous time, see Pissarides) and the corresponding dynamic equations in discrete time: Beveridge curve Job creation curve Wage curve • Thus, the typical demand and supply diagram is replaced. Note that Pissarides (2000) uses different letters (c are vacancy posting costs, beta is the bargaining power, p is the productivity, r is the discount factor). Lehrstuhl für VWL 12 Makroökonomik Graphical Illustration 1: Wages and Market Tightness Wage Curve Job Creation 13 Lehrstuhl für VWL Makroökonomik Graphical Illustration 2: Vacancies and Unemployment v Job Creation (JC) Beveridge Curve (BC) u 14 Lehrstuhl für VWL Makroökonomik Model Parametrization • • • • • • • Separation rate (s): 0.1 (exogenous) Discount rate (r): 0.012 Value of leisure (b): 0.4 Matching function ( ): 1.355*theta^-0.72 Bargaining power (beta): 0.72 ( Hosios rule) Cost of posting a vacancy (c): 0.213 The market tightness is normalized to 1 See Shimer (2005, p.38) 15 Lehrstuhl für VWL Makroökonomik Remember the Basic Model Structure 16 Lehrstuhl für VWL Makroökonomik Business Cycle Facts and the Model Taken from Shimer (2005, pp. 28 & 39). 17 Lehrstuhl für VWL Makroökonomik Some Analytics: Flexible Wage Case • The flexible wage case w A • We can rewrite the job-finding rate as 1 A jfr 1 1 1 • After some algebra, it can be shown that the elasticity of the job finding rate with respect to a is ln jfr 1 ln A 18 Lehrstuhl für VWL Makroökonomik Some Analytics: Wage Rigidity Case • Assume that the wage is a constant: wc • We can rewrite the job-finding rate as A c jfr 1 1 1 • After some algebra, it can be shown that the elasticity of the job finding rate with respect to a is ln jfr 1 A ln A Ac 19 Lehrstuhl für VWL Makroökonomik Lack of Volatility: Intuition 1 • After a productivity shock, the present value of a job (J) and the present value of a vacancy (V) increases. • The zero profit condition ensures that more vacancies are posted (as more firms enter the market). • However, the sensitivity of vacancies appears to be much too small. 20 Lehrstuhl für VWL Makroökonomik Lack of Volatility: Intuition 2 • Shimer (2005) has calibrated the bargaining power of households to 0.72. • This ensures Hosios’ (1990) rule ( efficiency). • Therefore, a big part of productivity increases is absorbed by households (wages). • This reduces the incentive for vacancy creation. • Thus, Shimer (2005) identifies the bargaining process as the core of the problem. 21 Lehrstuhl für VWL Makroökonomik Solution 1: Wage Rigidity • Hall (2005) proposes a sticky wage model as solution. • Intuition: When wages are sticky, households wages increase only incrementally or not at all after a productivity shock. • Therefore, productivity shocks affect firms’ profits by more than before. • More vacancies are posted and the labor market tightness is more sensitive than under Shimer’s calibration. • Innovation: The model does not interfere with the efficient formation of job matches (despite the wage rigidity). 22 Lehrstuhl für VWL Makroökonomik Problems with Hall’s Solution 1. The volatility of wages is zero 2. The correlation between the labor share and labor productivity is -1. See Hornstein et al. (2005, p. 44). 3. There is empirical evidence that wages for new hires are not rigid (Haefke et al, 2008). 23 Lehrstuhl für VWL Makroökonomik Solution 2: The Value of Leisure • Hagedorn and Manovskii (2008) set the value of leisure (b) to 0.955. • Thus, the difference between the present value of market activity and non-market activity is very small. • Workers’ bargaining power can be set to 0.052. • This leads to a very high wage share and a very low profit share. • Firms (relative) profits change a lot when productivity changes. • Therefore, the model economy’s volatilities increase. 24 Lehrstuhl für VWL Makroökonomik Problems with Hagedorn and Manovskii’s Solution • Hornstein et al. (2005) show that the sensitivity of the unemployment rate to unemployment benefit changes is much too big. • This elasticity is about 20 times larger than in Shimer’s (2005) calibration. • A 15 percent increase of unemployment benefits would double the unemployment rate. • This is very much at odds with microeconometric studies. • In addition: welfare issue! 25 Lehrstuhl für VWL Makroökonomik Conclusion • The search and matching model has difficulties replicating the amplification effects. • The Shimer puzzle can be fixed. However, this implies unrealistic other negative side effects. • Outlook: endogenous separations • Outlook: how flexible/rigid are wages for entrants? 26 Lehrstuhl für VWL Makroökonomik References • Hagedorn, Marcus, and Manovskii, Iourii (2008): “The Cyclical Behavior of Equilibrium Unemployment and Vacancies Revisited.” American Economic Review, Vol. 98, No. 4, pp. 1692-1706 . • Hall, Robert (2005): “Employment Fluctuations with Equilibrium Wage Stickiness.” American Economic Review, Vol. 95, No. 1, pp. 50–65. • Hornstein, Andreas, Krusell, Per, and Violante, Giovanni (2005): “Unemployment and Vacancy Fluctuations in the Matching Model: Inspecting the Mechanism.” Federal Reserve of Richmond Economic Quarterly, Vol. 91, No. 3, pp. 19-51. • Haefke, Christian, Sonntag, Markus, van Rens, Thijs (2008): “Wage Rigidity and Job Creation.” IZA Discussion Papers 3714 • Hosios, Arthur (1990). “On the Efficiency of Matching and Related Models of Search and Unemployment.” Review of Economic Studies, Vol. 57, No. 2, pp. 279–298. • Pissarides, Christopher (2000): “Equilibrium Unemployment.” MIT Press, Cambridge. • Shimer, Robert (2005): “The Cyclical Behavior of Equilibrium Unemployment and Vacancies.” American Economic Review, Vol. 95, No. 1, pp. 25-49. 27 Lehrstuhl für VWL Makroökonomik