This paper considers two problems that arise in determining the role of ability in explaining the level of and change in the rate of return to schooling. (1) Ability and schooling are so strongly dependent that it is not possible, over a wide range of variation in schooling and ability, to...

This paper derives simply computed closed-form expressions for the Average Treatment Effect (ATE), the effect of Treatment on the Treated (TT), Local Average Treatment Effect (LATE) and Marginal Treatment Effect (MTE) in a latent variable framework for both normal and non-normal models. The...

This paper exposits and relates two distinct approaches to bounding the average treatment effect. One approach, based on instrumental variables, is due to Manski (1990, 1994), who derives tight bounds on the average treatment effect under a mean independence form of the instrumental variables...