Using a nonparametric bounding method and data from the Panel Study of Income Dynamics, I examine the effect that growing up in a household that receives Aid to Families with Dependent Children (AFDC) has on welfare participation as a young adult. In light of the ambiguities created by the selection problem, a number of alternative assumptions and estimates are presented. While the data alone cannot be conclusive, the results generally strengthen the evidence that being exposed to AFDC as a child increases both the probability and the expected duration of future welfare participation.

Econometric analyses of treatment response commonly use instrumental variable (IV) assumptions to identify treatment effects. Yet the credibility of IV assumptions is often a matter of considerable disagreement. There is therefore good reason to consider weaker but more credible assumptions. To this end, we introduce monotone instrumental variable (MIV) assumptions and the important special case of monotone treatment selection (MTS). We study the identifying power of MIV assumptions alone and combined with the assumption of monotone treatment response (MTR). We present an empirical application using the MTS and MTR assumptions to place upper bounds on the returns to schooling

Despite dozens of studies, research on crime has struggled to reach consensus about the impact of right-to-carry (RTC) gun laws. With this in mind, we formalize and apply a class of bounded-variation assumptions that flexibly restrict the degree to which outcomes may vary across time and space. Using these assumptions, we present empirical analysis of the effect of RTC laws on violent and property crimes in Virginia, Maryland, and Illinois. Imposing specific assumptions that we believe worthy of consideration, we find that RTC laws increase some crimes, decrease other crimes, and have effects that vary over time for others.

To control the deer population, state game commissions regulate the types of deer that can be legally harvested. These regulations, however, might have an unintended effect on hunting-related accidents by changing the care hunters take when firing their rifles—a moral hazard effect—or changing the composition of hunters. Using detailed data on hunting accidents and regulations in Pennsylvania counties from 1990 to 2005, we find compelling evidence that harvesting restrictions increase the care hunters take in a manner consistent with moral hazard. Thus, these regulations have a positive safety externality.