Summary The "old" familiar diseases of cholera and typhoid remain a serious health threat in many developing countries. Health policy analysts often argue that vaccination against cholera and typhoid should be provided free because poor people cannot afford to pay for such vaccines and because...

The paper challenges the conventional wisdom that water and sanitation improvements and other preventive health interventions are always a wise economic investment. Costs and benefits are presented for six water, sanitation, and health programs—handwashing, sanitation, point-of-use filtration...