Efficiency in a matching model with heterogeneous agents: too many good or bad jobs?

This paper analyzes the efficiency of the equilibrium allocation in a matching model with two types of workers and jobs. The technology is such that high-skill workers can perform all jobs, while low-skill workers can only perform unskilled jobs. In this setup two types equilibria may occur. A cross-skill matching equilibrium in which high-skill workers accept all jobs and an ex-post segmentation equilibrium in which they accept only skilled jobs. Our first result shows that the equilibrium with ex-post bargaining is never efficient. Second, under Hosios'(1990) condition we show that low-skill workers are overvalued, while the opposite holds for high-skill workers. In equilibrium, firms therefore create too few unskilled jobs and too many skilled jobs. In addition, high-skill workers may decide to accept unskilled jobs while the efficient allocation features ex-post segmentation. Finally, in an extension we show that efficiency can be restored through taxation and we analyze how workers bargaining strength affects unemployment and the degree of skill-mismatch

EFFICIENCY IN A MATCHING MODEL WITH HETEROGENEOUS AGENTS: TOO MANY GOOD OR BAD JOBS?

This paper analyzes the efficiency of the equilibrium allocation in a matching model with two types of workers and jobs. The technology is such that high-skill workers can perform all jobs, while low-skill workers can only perform unskilled jobs. In this setup two types equilibria may occur. A “cross-skill matching equilibrium” in which high-skill workers accept all jobs and an “ex-post segmentation equilibrium” in which they accept only skilled jobs. Our first result shows that the equilibrium with ex-post bargaining is never efficient. Second, under Hosios´ (1990) condition we show that low-skill workers are overvalued, while the opposite holds for high-skill workers. In equilibrium, firms therefore create too few unskilled jobs and too many skilled jobs. In addition, high-skill workers may decide to accept unskilled jobs while the efficient allocation features ex-post segmentation. Finally, in an extension we show that efficiency can be restored through taxation and we analyze how workers´ bargaining strength affects unemployment and the degree of skill-mismatch.

Employment Fluctuations with Downward Wage Rigidity: The Role of Moral Hazard

This paper studies the cyclical dynamics of Mortensen and Pissarides' (1994) model of job creation and destruction when workers' effort is not perfectly observable, as in Shapiro and Stiglitz (1984). An occasionally-binding no-shirking constraint truncates the real wage distribution from below, making firms' share of surplus weakly procyclical, and may thus amplify fluctuations in hiring. It may also cause a burst of inefficient firing at the onset of a recession, separating matches that no longer have sufficient surplus for incentive compatibility. On the other hand, since marginal workers in booms know firms cannot commit to keep them in recessions, they place little value on their jobs and are expensive to motivate. For a realistic calibration, this last effect is by far the strongest; even a moderate degree of moral hazard can eliminate all fluctuation in the separation rate. This casts doubt on Ramey and Watson's (1997) "contractual fragility" mechanism, and means worker moral hazard only makes the "unemployment volatility puzzle" worse. However, moral hazard has potential to explain other labor market facts, because it is consistent with small but clearly countercyclical fluctuations in separation rates, and a robust Beveridge curve.job matching, shirking, efficiency wages, endogenous separation, contractual fragility

Search, Mismatch and Unemployment

Matching, ex post bargaining, heterogeneity, efficiency

Efficiency in a matching model with heterogeneous agents: too many good or bad jobs?.

This paper analyzes the efficiency of the equilibrium allocation in a matching model with two types of workers and jobs. The technology is such that high-skill workers can perform all jobs, while low-skill workers can only perform unskilled jobs. In this setup two types equilibria may occur. A cross-skill matching equilibrium in which high-skill workers accept all jobs and an ex-post segmentation equilibrium in which they accept only skilled jobs. Our first result shows that the equilibrium with ex-post bargaining is never efficient. Second, under Hosios'(1990) condition we show that low-skill workers are overvalued, while the opposite holds for high-skill workers. In equilibrium, firms therefore create too few unskilled jobs and too many skilled jobs. In addition, high-skill workers may decide to accept unskilled jobs while the efficient allocation features ex-post segmentation. Finally, in an extension we show that efficiency can be restored through taxation and we analyze how workers bargaining strength affects unemployment and the degree of skill-mismatch.

Can job competition prevent hold-ups?

We consider an economy in which firms need to invest in capital before they can advertise a job, while applicants may have to compete for jobs. Our aim to investigate how this competition affects the investment decisions of firms. Our first finding shows that the economy always generates the right number of jobs. However, with random search firms under-invest in capital. In contrast, if workers can direct their search towards firms with different capital levels, the equilibrium is efficient. This result contrasts sharply with the predictions of models with ex post wage bargaining that never yield an efficien allocation. Moreover, our results extend the efficiency of auction mechanisms to an environment with non-contractible investments

Employment Fluctuations with Downward Wage Rigidity

This paper considers a dynamic matching model with imperfectly observable worker effort as in Shapiro and Stiglitz (1994). In our economy the no-shirking condition endogenously imposes real wage rigidity on the matching market. This generates "contractual fragility" and inefficient separations as in Ramey and Watson (1997). Nonetheless, our main finding is that imperfectly observable effort smoothes job destruction over the cycle. The reason is that firms are forced, in good states, to terminate some marginal jobs that they cannot commit to maintain in bad states. This time-inconsistency problem casts doubts on the importance of inefficient churning as an explanation of observed employment fluctuations. On the other hand, the no-shirking condition implies that the surplus share of firms is pro-cyclical, which can amplify fluctuations in job creation. Thus, our model is consistent with recent evidence that job creation is more important than job destruction in driving labor market fluctuations, and it therefore also tends to generate a robust Beveridge curve.Job matching, wage rigidity, efficiency wages, contractual fragility

UV-B exposure, ROS, and stress: inseparable companions or loosely linked associates?

Ultraviolet-B (UV-B) radiation has long been perceived as a stressor. However, a conceptual U-turn has taken place, and UV-B damage is now considered rare. We question whether UV-stress and UV-B-induced reactive oxygen species (ROS) are still relevant concepts, and if ROS-mediated signaling contributes to UV-B acclimation. Measurements of antioxidants and of antioxidant genes show that both low and high UV-B doses alter ROS metabolism. Yet, there is no evidence that ROS control gene expression under low UV-B. Instead, expression of antioxidant genes is linked to the UV RESISTANCE LOCUS 8 pathway. We hypothesize that low UVB doses cause ‘eustress’ (good stress) and that stimulispecific signaling pathways pre-dispose plants to a state of low alert that includes activation of antioxidant defenses.Funding agencies are:COST Action  FA0906UV4Growth  Faculty of Business, Science, and Technology at Örebro University  Science Foundation Ireland (SFI)  11/RFP.1/EOB/3303 Hungarian Scientific Research Fund  OTKA NN-85349 UV-B-fotobiologi: mekanismer för perception och cellulära response

A Positive Analysis of Targeted Employment Protection Legislation

In many countries, Employment Protection Legislation (EPL) establishes less strict dismissal procedures for specific groups of workers. This paper builds a simple matching model with heterogeneous workers in order to analyze this feature of EPL. We use the model to analyze the effects of reforms targeted at lowering the firing costs of a particular group of workers, and compare the results with those stemming from a comprehensive reform that reduces firing costs for all workers. The model is calibrated for the Spanish economy, where an important reform of this kind took place in 1997. Overall, our results point out that EPL reforms achieve the largest reduction in unemployment when they are targeted to workers with lower and more volatile productivity.Publicad

CAN JOB COMPETITION PREVENT HOLD-UPS?

We consider an economy in which firms need to invest in capital before they can advertise a job, while applicants may have to compete for jobs. Our aim to investigate how this competition affects the investment decisions of firms. Our first finding shows that the economy always generates the right number of jobs. However, with random search firms under-invest in capital. In contrast, if workers can direct their search towards firms with different capital levels, the equilibrium is efficient. This result contrasts sharply with the predictions of models with ex post wage bargaining that never yield an efficien allocation. Moreover, our results extend the efficiency of auction mechanisms to an environment with non-contractible investments.