We argue that poverty can perpetuate itself by undermining the capacity for self-control. In line with a distinguished psychological literature, we consider modes of self-control that involve the self-imposed use of contingent punishments and rewards. We study settings in which consumers with quasi-hyperbolic preferences confront an otherwise standard intertemporal allocation problem with credit constraints. Our main result demonstrates that low initial assets can limit self-control, trapping people in poverty, while individuals with high initial assets can accumulate indefinitely. Thus, even temporary policies that initiate accumulation among the poor may be effective. We examine implications concerning the effect of access to credit on saving, the demand for commitment devices, the design of financial accounts to promote accumulation, and the variation of the marginal propensity to consume across income from different sources. We also explore the nature of optimal self-control, demonstrating that it has a simple and behaviorally plausible structure that is immune to self-renegotiation.

Default contribution rates for 401(k) pension plans powerfully influence choices. Potential causes include opt-out costs, procrastination, inattention, and psychological anchoring. Using realistically parameterized models, we show how the optimal default, the magnitude of the welfare effects, and the degree of normative ambiguity depend on the behavioral model, the scope of the choice domain deemed welfare-relevant, the use of penalties for passive choice, and other 401(k) plan features. While results are theory-specific, our analysis provides reasonably robust justifications for setting the default either at the highest contribution rate matched by the employer or—contrary to common wisdom—at zero. (JEL D14, D91, J26, J32)