We provide an overidentification test for a nonparametric treatment model where individuals are allowed to select into treatment based on unobserved gains. Our test can be used to test the validity of instruments in a framework with essential heterogeneity (Imbens and Angrist 1994). The...

"On ne peut penser la Première Guerre mondiale en ignorant ce qui fut une conséquence fondamentale de celle-ci : l'essor considérable du syndicalisme dans le monde, son rôle accru dans les rapports sociaux ou les décisions des états. Vient, dès la deuxième moitié de la guerre, le temps...

"La Grande Guerre constitue un tournant majeur dans la gestion des finances publiques au XXe siècle. En préférant essentiellement l'emprunt à l'impôt pour faire face aux dépenses de guerre, les pays belligérants ouvrent en effet le cycle durable du déficit budgétaire, de l'endettement,...

This paper examines the causal effect of volume on outcome on the example of patients with a hip fracture. We use an instrumental variable approach and consider both the practice-makes-perfect and selective-referral hypothesis as well as unobserved patient heterogeneity. Our results indicate...

This paper examines recent trends in employment patterns on the labor market for youth and changing returns to early employment stability over the past four decades. True state dependence is identified by exploiting exogenous variation in aggregate labor market conditions induced by differences...

In this paper I analyze the relationship between unemployment and criminal activity. Using a unique panel data set on German counties covering the years 2003 to 2009, I estimate the effect of unemployment on crime rates for different kind of offenses. I extensively control for potential...