Reduced rank regression (RRR) models with time varying heterogeneity are considered. Standard information criteria for selecting cointegrating rank are shown to be weakly consistent in semiparametric RRR models in which the errors have general nonparametric short memory components and shifting...

A breakdown frontier is the boundary between the set of assumptions which lead to a specific conclusion and those which do not. In a potential outcomes model with a binary treatment, we consider two conclusions: First, that ATE is at least a specific value (e.g., nonnegative) and second that the...

Using a theoretical model where students care about achievement rank, I study effort choices in the classroom and show that rank concerns generate peer effects. The model's key empirical prediction is that the effect on own achievement of increasing the dispersion in peer cost of effort is...