Many social experiments are run in multiple waves, or are replications of earlier social experiments. In principle, the sampling design can be modified in later stages or replications to allow for more efficient estimation of causal effects. We consider the design of a two-stage experiment for...

We review the theoretical and empirical literature on commitment devices. A commitment device is any arrangement, entered into by an individual, with the aim of making it easier to fulfill his or her own future plans. We argue that there is growing empirical evidence supporting the proposition...

We develop and test a simple model of limited attention in intertemporal choice. The model posits that individuals fully attend to consumption in all periods but fail to attend to some future lumpy expenditure opportunities. This asymmetry generates some predictions that overlap with models of...