We use exogenous variation in Social Security payments created by the Social Security benefits notch to estimate how retirees' use of prescription medications responds to changes in their incomes. In contrast to estimates obtained using ordinary least squares, instrumental variables estimates...

Medicareamp;apos;s Part D offers heavily subsidized new drug coverage to 22.5 million seniors to date, of whom 16.5 million are in stand-alone drug plans (Department of Health and Human Services, 2006). The government delegated the delivery of the benefit to private insurance companies arguing...