Every year, the US Bureau of Labor Statistics releases projections on the prospects for the job market over the next 10 years. This year’s projections, released yesterday, find that over the next decade, the US workforce is likely to see a tsunami of elderly workers. The share of workers over the age of 75 is projected to grow from 1.8 million in 2018 to 3.7 million in 2028.

At 105% growth, that is the fastest growth projected for any age group in the US. It is followed by 65- to 74-year-old workers, who are expected to grow by about 51%. The 35- to 44-year-old age group is the only other age group projected to grow, thanks to the large size of that age cohort, who are often the children of the baby boomers.

Why are people working longer? In addition to people simply being healthier and living longer, financial reasons including years of stagnant real wages and a shift away from traditional pensions in the private sector, as well as the increase in the number of people working in less labor-intensive occupations, contribute to the aging American workforce.

But the trend also varies by educational attainment. Census data shows that the share of Americans with bachelor’s degrees who were working into their 70s reached nearly 20% in 2018. For those with a high school degree or less, the percentage of those working in their 70s had risen to around 10%, while those with some college education were in the middle at around 15%.

The degree attainment helps shed light on the reasons people choose to labor longer. Highly educated workers were more likely in professional occupations where they tended to enjoy the job more, choosing to work longer more for the social benefits than for financial reasons. In addition, being at work helps prevent feelings of loneliness, especially for men.

Meanwhile, workers in more physical jobs are more likely to look forward to retiring, which suggests that those who stay on are more likely doing so for financial reasons.