In a large class of hazard models with proportional unobserved heterogeneity, the distribution of the heterogeneity among survivors converges to a gamma distribution. This convergence is often rapid. We derive this result as a general result for exponential mixtures and explore its implications...

This paper implements a method to identify and estimate treatment effects in a dynamic setting where treatments may occur at any point in time. By relating the standard matching approach to the timing-of-events approach, it demonstrates that effects of the treatment on the treated at a given...

I expose the risk of false discoveries in the context of multiple treatment effects. A false discovery is a nonexistent effect that is falsely labeled as statistically significant by its individual t-value. Labeling nonexistent effects as statistically significant has wide-ranging academic and...

A recent experimental programme for unemployed welfare recipients in the UK found that temporary earnings supplements combined with post-employment services led to a sustained rise in employment. This paper examines whether this was due to increases in employment entry or to reductions in...

We employ survival analysis to study the duration of U.S. imports. Our findings indicate international trade is far more dynamic than previously thought. The median duration of exporting a product to the U.S. is very short, on the order of two to four years. There is negative duration...

Many panel data methods, while allowing for general dependence between covariates and time-invariant agent-specific heterogeneity, place strong a priori restrictions on feedback: how past outcomes, covariates, and heterogeneity map into future covariate levels. Ruling out feedback entirely, as...

The objective of the article has consisted of a cross-sectional and longitudinal analysis of the economic poverty state during the period 1985-1995, using the Panel Household Budget Survey for this period of time. The three aspects of poverty incidence, intensity and inequality in the left tail...

The vocational employment training program is the most ambitious and expensive training program in Sweden and a cornerstone of labor market policy. We analyze its causal effects on the individual transition rate from unemployment to employment by exploiting variation in the timing of treatment...

This paper documents the relative importance of firm, industry and aggregate factors on the post-entry performance of new firms. This study utilizes a unique administrative dataset, T2LEAP, which contains employment and balance sheet information for all incorporated Canadian firms. The data...

We study the identification of a mixed proportional hazard model with lagged duration dependence when data provide multiple outcomes per stratum. Within strata variation is exploited to non-parametrically identify lagged duration dependence in more general models than in the literature.