We combine administrative data from the bank with six waves of detailed survey data – to study how commitment impacted respondents’ financial behavior both at the partner bank and more broadly. First, we find robust demand for commitment. Seventy-two percent of individuals in the treatment group signed up for the product, and just 13 percent of those who signed up dropped out before the 18-month savings cycle ended. Second, the product more than doubled balances at the partner bank both during and after the commitment period. We also observe a marginally significant 6 percentage point (18 percent) decline in overdrafts in the six months following the release of the commitment amount. In the longer run, however, treatment effects on overdrafts disappear.

Our third main result underscores the importance of taking a broader view of consumers’ finances when evaluating savings products. Although the commitment product did not crowd out other cash savings, we do observe a significant increase in the share of respondents who took on new debt during the commitment period. Point estimates on debt stocks are roughly equal to point estimates on total savings, and as a result our treatment estimates on net savings (savings less debt) are close to zero and not statistically significant.

This interpretation changes dramatically when studying heterogeneity in treatment effects by baseline overdrafter status, however. “Heavy overdrafters” (those with above median overdraft histories at baseline) did save more at the partner bank during the commitment period, but this treatment effect disappears after the commitment amount is released. Moreover, the product significantly _decreased_ heavy overdrafters’ other formal sector savings during the commitment period while increasing the rate of debt taking. These results are consistent with the hypothesis that heavy overdrafters are naïve hyperbolic discounters, who end up undoing their commitment by borrowing. “Light overdrafters” (those with belowmedian histories) exhibited a very different response: the commitment product significantly increased other formal sector savings both during and after the commitment period, with no significant impact on debt. This suggests that light overdrafters benefited from the savings product through a channel other than time inconsistency.

The main contribution of our paper is to explore the extent to which commitment is crowded out by other sources of liquidity, while directly exploring the pitfalls of commitment. To date, much of the research on behavioral savings products in development economics focuses on savings held at partner financial institutions, or savings without accounting for debt (for a review of recent work see Karlan et al. 2014). Our findings highlight the need for future work to cast a broader net when assessing the promise of commitment for improving the financial lives of the poor.<sup>2</sup> Our work also builds on John (2017), who finds that over

> 2In this way our paper is related to a growing literature that seeks to understand the net effects of retirement savings programs in developed country contexts (Poterba et al., 1996; Benjamin, 2003; Engelhardt

3