Using data from a field experiment in Kenya, we document that providing individuals with simple informal savings technologies can substantially increase investment in preventative health and reduce vulnerability to health shocks. Simply providing a safe place to keep money was sufficient to increase health savings by 66 percent. Adding an earmarking feature was only helpful when funds were put toward emergencies, or for individuals that are frequently taxed by friends and relatives. Group-based savings and credit schemes had very large effects.

Many subjects in lab experiments exhibit small-stakes risk aversion, consistent with loss aversion. Those with greater math skills are less likely to show small-stakes risk aversion. We argue that departures from expected utility maximization may help explain why many firms in developing countries leave high expected return investments unexploited. We show that among a sample of Kenyan shopkeepers, inventories are negatively associated with small-stakes risk aversion and positively associated with math skills.