The appropriateness of many high-cost loan regulations depends on whether demand is driven by financial conditions ("misfortunes") or imperfect decisions ("mistakes"). Bank records from Iceland show borrowers have especially low liquidity just before getting a loan. Borrowers exhibit lower decision-making ability (DMA) in linked choice experiments: 45% of loan dollars go to the bottom 20% of the DMA distribution. Standard determinants of demand do not explain this relationship, which is also mirrored by the relationship between DMA and an unambiguous "mistake." Both "misfortune" and "mistake" thus appear to drive demand.

We study the effect of financial resources on decision-making. Low-income U.S. households are randomly assigned to receive an online survey before or after payday. The survey collects measures of cognitive function and administers risk and intertemporal choice tasks. The study design generates variation in cash, checking and savings balances, and expenditures. Before-payday participants behave as if they are more present-biased when making intertemporal choices about monetary rewards but not when making intertemporal choices about non-monetary real-effort tasks. Nor do we find before-after differences in risk-taking, the quality of decision-making, the performance in cognitive function tasks, or in heuristic judgments.