Family Policies and Children's School Achievement in Single‐ Versus Two‐Parent Families

We investigate the gap in math and science achievement of third‐ and fourth‐graders who live with a single parent versus those who live with two parents in 11 countries. The United States and New Zealand rank last among the countries we compare in terms of the equality of achievement between children from single‐parent families and those from two‐parent homes. Following a multilevel analysis, we find single parenthood to be less detrimental when family policies equalize resources between single‐ and two‐parent families. In addition, the single‐ and two‐parent achievement gap is greater in countries where single‐parent families are more prevalent. We conclude that national family policies can offset the negative academic outcomes of single parenthood.     

The Nonparametric Identification of Treatment Effects in Duration Models

This paper analyzes the specification and identification of causal multivariate duration models. We focus on the case in which one duration concerns the point in time a treatment is initiated and we are interested in the effect of this treatment on some outcome duration. We define “no anticipation of treatment” and relate it to a common assumption in biostatistics. We show that (i) no anticipation and (ii) randomized treatment assignment can be imposed without restricting the observational data. We impose (i) but not (ii) and prove identification of models that impose some structure. We allow for dependent unobserved heterogeneity and we do not exploit exclusion restrictions on covariates. We provide results for both single‐spell and multiple‐spell data. The timing of events conveys useful information on the treatment effect.     

Last‐In First‐Out Oligopoly Dynamics

This paper extends the static analysis of oligopoly structure into an infinite‐horizon setting with sunk costs and demand uncertainty. The observation that exit rates decline with firm age motivates the assumption of last‐in first‐out dynamics: An entrant expects to produce no longer than any incumbent. This selects an essentially unique Markov‐perfect equilibrium. With mild restrictions on the demand shocks, sequences of thresholds describe firms' equilibrium entry and survival decisions. Bresnahan and Reiss' (1993) empirical analysis of oligopolists' entry and exit assumes that such thresholds govern the evolution of the number of competitors. Our analysis provides an infinite‐horizon game‐theoretic foundation for that structure.