Two cornerstones of empirical and policy analysis of firms in industrial organization, macro and labor are the determinants of the firm size distribution, and the determinants of sorting between workers and firms. We propose a unifying theory of production where management resolves a tradeoff between hiring more versus better workers. The span of control or size is therefore intimately intertwined with the sorting pattern. We provide a condition for sorting that captures this tradeoff between the quantity and quality of workers and that generalizes Becker’s sorting condition. A system of differential equations determines the equilibrium allocation, the firm size and wages, and allows us to characterize the allocation of the quality and quantity of labor to firms of different productivity. We show that our model nests a large number of widely used existing models. We also augment the model to incorporate labor market frictions in the presence of sorting with large firms.
Assortative Matching with Large Firms
Econometrica. 2018 86(1): 85-132. With Jan Eeckhout.
When heterogeneous firms can choose both how many and which workers to hire, we illustrate consequences for firm-size and wage inequality.
Note a correction for the condition with capital: corrigendum.
Economic Journal, 2021 131: 713-744. With Ericson, Spinnewijn &, Starc Demand for insurance can be driven by high risk aversion or high risk, and we show how to separate the two using observed market shares. Go to paper
American Economic Journal - Macroeconomics, forthcoming 2022, with Michèle Belot and Paul Muller. In a field experiment, we study how job seekers respond to posted wages by assigning wages randomly to pairs of otherwise similar vacancies in a large number of professions. Higher wages attract significantly more interest, but still a non-trivial number of applicants only reveal an interest in the low wage vacancy - qualitatively in line with a directed search model with multiple applications and on-the-job search. Go to paper
Review of Economic Studies, 2019 86(4): 1411-1447. With Michèle Belot and Paul Muller. We develop and evaluate experimentally a novel tool that redesigns the job search process by providing tailored online advice about related occupations. Go to paper
American Economic Review P&P, 2017, 107(5): 158–162 With J. Greenwood, C. Santos & M. Tertilt. In a quantitative equilibrium model of sexual behavior and HIV/AIDS transmission we study policies that encourage long-term partnerships. Go to paper
International Economic Review, 2012, Vol 53 (1), 1-21. With M. Galenianos. We study a finite directed-search wage posting game among heterogeneous firms (allowing for risk aversion, moral hazard,…), including limit theorems. Go to paper
Journal of Political Economy, 2017, 124(1), 224-264. With G. Grossman & E. Helpman. (simulations, matlab). We introduce two-sided heterogeneity into a Hecksher-Ohlin-style trade model to study factor reallocation and wage inequality within and across sectors. Go to paper