Essays on labor economics : sorting, inequality and technological change[Essais sur l'économie du travail : appariement, inégalité et changement technologique]

This thesis examines the themes of sorting, inequality and the impact of technological change on the labor market. In particular, it addresses the questions of how workers sort within and between firms and how this influences labor market inequality, both in the workforce as a while, as well as between demographic and skill groups. It also considers how changes in technology affects the labor market conditions faced by workers and firms. These questions are tackled over three chapters. The first chapter, entitled `Multidimensional heterogeneity and matching in a frictional labor market - an application to polarization' deals with the sorting of workers to firms along multidimensional characteristics and quantifies the impact of technological change on the evolution of sorting patterns, wages and employment outcomes of different skill and demographic groups. I construct a model of directed search with two-sided multidimensional heterogeneity and estimate the model on US data. I find that production complementarities between cognitive and interpersonal skills and tasks have increased, relative to hat between manual skills and manual tasks. This change in production technology accounts for a large part of wage and job polarization in the US. Also, despite being gender-blind, the model can explain a substantial fraction of the narrowing of gender wage and job rank gaps from the 1980s to the present day. The second chapter, entitled `Intra-firm hierarchies and gender gaps' and coauthored with Nicolo Dalvit and Aseem Patel, studies the sorting of women into layers of hierarchy within firms, using administrative French data, and examines the incidence of gender wage and employment gaps across hierarchies over time. Further, by exploiting a policy on corporate board quotas in France, it assesses the impact of an increase in female leadership on gender wage and employment outcomes within firms. We find that hierarchies matter in gender wage and employment gaps. Gender wage and employment gaps increase with each layer of firm hierarchy, even if these gaps narrow more over time in the upper layers. In addition, improvements in top female leadership has differing impacts across hierarchies. While a greater share of female corporate board members narrows the gender wage gap in top layers of hierarchy, it has no such impact on lower layers. Instead, it increases the share of women in lower layers working part-time, at the expense of full-time employment. The opposite is true for women in upper layers. The third chapter, `Occupational Shortage and Labor Market Adjustments: a Theory of Islands', coauthored with Riccardo Zago, addresses the incidence of occupational shortage, and assesses whether it leads to wage and employment adjustments. Using a unique dataset on reported vacancies that firms find difficult to fill, we document the incidence of shortage across regions, industries and occupation groups. We find that shortage only leads to wage and employment adjustments in non-routine occupations, but not in routine occupations. We show how the secular decline of the routine occupations, caused by technological change, can account for the persistence in shortage in the routine sector and its inability to adjust.