Enabling farmers to prepay for fertilizer when they had cash on hand was effective in promoting fertilizer adoption.

Small incentives for parents, coupled with reliable services at convenient mobile clinics, increased full immunization rates sixfold. This approach was twice as cost-effective as improving service reliability without incentives.

Recent evidence from randomized studies of microfinance indicate that poor people face various limits in their ability to capitalize on financial opportunities. Product design matters, and inexpensive design tweaks may help the poor to benefit more from financial products and services.

A retail-sector subsidy for effective antimalarials in Kenya greatly increased access among the most vulnerable, but design matters: finding the right price and providing diagnostic tests are important tools for limiting unnecessary treatment.

A quota system for female village leaders in India changed perceptions of women’s abilities, improved women’s electoral chances, and raised aspirations and educational attainment for adolescent girls.

Choosing local infrastructure projects by direct election, rather than through representatives, had a small effect on the types of projects selected but a large impact on citizen satisfaction in Indonesia.

A month-long classroom “Read-A-Thon” program improved children’s reading habits and skills in the Philippines.

In Odisha, India improved cooking stoves did not reduce smoke exposure, improve health, or reduce fuel usage of recipients because they were not used regularly and recipients did not invest to maintain them properly.

Protecting naturally occurring springs with simple infrastructure significantly improved source water quality and reduced the incidence of diarrhea in young children by one-quarter.

Changing the market for environmental audits to incentivize accurate reporting in Gujarat, India made auditors more likely to report the truth about industrial plants’ pollution levels. In response, industrial plants polluted less.

If microcredit, as traditionally implemented, is being done just as well by for-profits, where to for non-profits? Dean Karlan lays out three important roles that non-profits can play in the financial inclusion arena.

The Oregon Health Insurance Experiment found that covering the uninsured with Medicaid increased the use of health care, including primary care, hospitalizations, and emergency room visits; diminished financial strain; and reduced depression. There was no statistically significant impact on physical...

Community block grants improved health and education in Indonesian villages, and adding performance incentives sped up improvements in health.

Cash transfers directed to female caregivers in Nicaragua led to gains in child-development outcomes that persisted beyond the duration of the program.

A community-based monitoring program in Uganda led to large and sustained increases in health care utilization and improvements in child health. The key to success was providing communities with information on the performance of local health care providers.