This question was first posed by John Rae writing in the early nineteenth century. As Frederick and colleagues 30 explain, "Like [his contemporary] Adam Smith, Rae sought to determine why wealth differed among nations. Smith had argued that national wealth was determined by the amount of labor allocated to the production of capital, but Rae recognized that this account was incomplete because it failed to explain the determinants of this allocation. In Rae's view, the missing factor was 'the effective desire of accumulation," which determines the "rate of time preference." The rate of time preference is a mathematical representation of the tendency individuals have to weight the present more heavily than the future when making decisions. It summarizes how willing consumers are to delay immediate consumption and instead invest or save their income. 30 Thus, the relationship between the rate of time preference and savings behavior at the individual level can be linked to income growth and disparities at the aggregate level. Studies by psychologists and economists have shown that the poor discount the future more steeply than the wealthy. 31 This result has given rise to the view that the poor are impatient or, more pejoratively, lack self-control. However, this rationale fails to account for the uncertainty and risks associated with living in poverty. In particular, how do health status and expectation of longevity influence one's willingness to make trade-offs over time? Recent evidence from Sri Lanka sheds light on this question. Jayachandra and Lleras-Muney 32 examined how a sudden drop in maternal mortality between 1946 and 1953 sharply increased the life expectancy of girls. This increase in turn led to greater investment in their education: Jayachandra and Lleras-Muney 32 found that, for every extra year of life expectancy, literacy among girls increased by 0.7 percentage points (2%) and years of education increased by 0.11 years (3%). At Partners In Health, we often use the phrase antidote to despair to describe our work. Translating the language of social justice into the language of economics, the antidote is the extended time horizon afforded by longevity. Knowing that a healthy and well-fed tomorrow awaits may affect the psychology of those living in poverty. The impact of this health-led hope on investments in microenterprise, education, and complementary health inputs has yet to be fully measured.