The share of the population made up of working-age people in Indianapolis and Central Indiana will diminish in the next two decades. This chart shows how the age balance of the county population has changed over the past 15 years.

Source: American Community Survey, 2005

As the baby-boom generation has aged during the past half-century, it has always been the largest in the population. During the 1950s, baby boomers were children. During the 1960s and 1970s, they were students. And during the 1980s and 1990s, they were in the workforce.

Now and in years to come, the boomers will be making the change from workforce to retirement or semi-retirement. Their numbers will diminish, but they will create a new demand for health care and retirement facilities, and eventually burial plots, just as in earlier times they caused society to build more schools and houses, make more goods and create more jobs.

Still, the significance of the baby boom is sometimes overstated. The boomer cohort is diminishing steadily both in terms of raw number and as a share of U.S. population. Seventy-nine million people were born between 1946 and 1964, and they were at one time more than 40 percent of America’s population. But by 2000, the number of boomers had fallen to 73 million, or only 26.3 percent of the population.