One in eight Americans today is over the age of 65, and the proportion will increase dramatically in the future. The aging of the population has begun to drive tax and budget decisions and the federal policy agenda, as policy makers and voters look ahead to enormous demands on the health and income security programs. Indeed, it is projected that Medicare and Social Security will constitute nearly half the federal budget in the year 2030, when one in five Americans will be over 65.

In Policies for an Aging Society, Stuart H. Altman and David I. Shactman have gathered experts in...