NBER Publications by William Jack

Mobile money is a tool that allows individuals to make financial transactions using cell phone technology. In this paper, we report initial results of two rounds of a large survey of households in Kenya, the country that has seen perhaps the most rapid and widespread growth of a mobile money product – known locally as M‐PESA – in the developing world. We first summarize the mechanics of M-PESA, and review its potential economic impacts. We then document the sequencing of adoption across households according to income and wealth, location, gender, and other socio‐economic characteristics, as well as the purposes for which the technology is used, including saving, sending and receiving remittances, and direct purchases of goods and services. In addition, we report findings from a survey of M...

Flexible Spending Accounts (FSAs) subsidize out-of-pocket health expenses not covered by employer-provided health insurance, making health care cheaper ex post, but also reducing the incentive to insure. We use a cross section of .rm-level data to show that FSAs are indeed associated with reduced insurance coverage, and to evaluate the welfare consequences of this shift. Correcting for selection effects we find that FSAs are associated with insurance contracts that have coinsurance rates about 7 percentage points higher, relative to a sample average coinsurance rate of 17 percent. Meanwhile, coinsurance rates net of the subsidy are approximately unchanged, providing evidence that FSAs are welfare-neutral. These results show that FSAs may explain a significant fraction of the shift in heal...