AMERICANS ARE LIVING longer with each generation. According to the U.S. Census Bureau, half of this country's population was under age twenty in 1860. Few could expect to live to age sixty-five. In 1960, 6 out of every 100 Americans were age sixty-five or older. Just thirty-five years later, that figure had more than doubled, with 33.2 million Americans—more than 12 percent—over age sixty-five. Analysts project that by 2030, the number of Americans over age sixty-five will again double to 65 million—nearly 1 in 4.

The aging of America

Advances in medical technology and better living conditions share most of the credit for such dramatic increases. However, the rise in the number of Americans over age sixty-five is also the result of a dramatic increase in births between 1946 and 1964. During that period, 77 million babies were born in the United States&mdash...