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.

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.