Working papers

« Waiting for the Prince Charming: Fixed-Term Contracts as Stopgaps »

See the paper and the code on GitHub. Try the latter online using Binder. A discussion about the paper is available on the NEP-DGE blog.

In this paper, I build a simple Mortensen-Pissarides model embedding a dual labor market. I derive conditions for the existence of an equilibrium with coexisting strongly protected open-ended contracts and exogeneously short fixed-term contracts. I also study dynamics after a reform on employment protection legislation. Temporary contracts play the role of fillers while permanent contracts are used to lock up high-productivity matches. High firing costs favor the emergence of a dual equilibrium. Employment protection legislation encourages the resort to temporary employment in job creation. This scheme is intertwined with a general-equilibrium effect: permanent contracts represent the bulk of employed workers and a more stringent employment protection reduces aggregate job destruction. This pushes down unemployment and in turn reduces job creation flows through temporary contracts. The model is calibrated to match the French labor market. Policy experiments demonstrate that there is no joint gain in employment and social welfare through reforms on firing costs around the baseline economy. The optimal policy consists in implementing a unique open-ended contract with a strong cut in firing costs. Increases in firing costs within a dual labor market lead to a sluggish adjustment, while large cuts in firing costs lead to a quick one. The adjustment time of the labor market is highly non-monotonous between these two extremes. Policy-related uncertainty significantly strengthens fixed-term employment on behalf of open-ended employment. Considering extensions, I draw conclusions on the inability of a large class of random-matching models to mimic the distribution of temporary contracts’ duration while maintaining possible the expiring temporary contracts’ conversion into permanent contracts.

« Fluctuations in a Dual Labor Market »

See the paper and the code on GitHub.

I build a New-Keynesian dynamic stochastic general-equilibrium model with a dual labor market. Firms and workers meet through a matching technology à-la Diamond-Mortensen-Pissarides and face a trade-off between productivity and flexibility at the hiring stage. All else equal, open-ended contracts are more productive than fixed-term contracts, but they embed a firing cost. The share of fixed-term contracts in job creation fluctuates endogenously, which enables to assess the resort to temporary contracts along the cycle and its response to different shocks. I estimate the model using a first-order perturbation method and classic Bayesian procedures with macroeconomic data from the Euro area. I find that the share of fixed-term contracts in job creation is counter-cyclical. The agents react to shocks essentially through the job creation margin and the contractual composition of the hires. Moreover, a general-equilibrium effect arises; the substitution between fixed-term and open-ended contracts at the hiring stage influences the job seekers’ stock, which in turn impacts job creation. Using my previous estimates and solving the model with a third-order perturbation method, I find that fixed-term employment reacts to negative aggregate demand shocks and uncertainty shocks oppositely. This result suggests that fixed-term employment could be used to identify uncertainty shocks in future research. As for inflation, changes in firing costs do not alter its dynamics as long as open-ended and fixed-term matches do not differ much in productivity all else equal.

Research in Progress

« Martial Sorting and Wealth », with Mehdi Bartal

Americans tend to marry their like, and this is more and more the case. Is marital sorting an important driver of wealth inequality in the US? To answer this question, we propose a life cycle model with discount factor heterogeneity, endogenous marriage and wealth accumulation under borrowing constraints. We solve the intra-household consumption-savings problem when spouses have heterogeneous preferences. We highlight that consumption gains from marriage are crucial to the analysis. We calibrate the model on US data and show that both participation in the marriage market and marital sorting along discount factors have non-negligible impacts on the aggregate level of wealth concentration. Our model predicts that marriage decline reduces inequality while rising marital sorting widens the wealth gap between Americans.

« The Capital and Labor Principle », with Marco Ranaldi