Here is the labor force participation rate for prime-age men and women over the past two decades:
In 20 years, the trend participation rate has dropped 4 percentage points for men and 3 percentage points for women. This is only for people aged 25-54, so it’s not about boomers retiring. It’s been dropping steadily, so it’s not about recessions. It’s not about tax cuts or tax increases. The unemployment rate is currently 4.1 percent, so it’s not about a lack of jobs. Nor is this happening in the rest of the world:
Whatever the reason, this decline represents about 4 million people who would be working if participation rates had stayed steady. Why aren’t they? Does it represent the 5 million manufacturing workers who have lost jobs since 1997, some of whom have quit working rather than take other jobs? Is it about China? But if so, why is everyone else immune? Is it the rise of disability—or is that effect rather than cause? Or something else? It is a mystery.