Many North American college students have trouble satisfying degree requirements in a timely manner. This paper reports on a randomized field experiment involving two strategies designed to improve academic performance among entering full-time undergraduates at a large Canadian university. One...

Problems of sample selection arise in the analysis of both experimental and non-experimental data. In clinical trials to evaluate the impact of an intervention on health and mortality, treatment assignment is typically nonrandom in a sample of survivors even if the original assignment is random....

The average effect of intervention or treatment is a parameter of interest in both epidemiology and econometrics. A key difference between applications in the two fields is that epidemiologic research is more likely to involve qualitative outcomes and nonlinear models. An example is the recent...