The other main driver of economic growth—output per worker—has been less predictable. Annual increases averaged 2.3% between 1950 and 1973, fell to 0.7% between 1974 and 1981, then surged to 2% in the 1990s before falling back to about 1.3% in 2001-20.

Galston argues that ” international experience suggests that there is little government can do to increase birthrates. But there is much that can be done to improve labor-force participation. Government can make it easier for women to remain in the workforce, for those formerly incarcerated to re-enter it, for young adults not bound for college to find technical training and for aging Americans to work part time if they choose, among other things.”

But Galston also sees a possible solution to America’s immigration crisis emerging from the labor supply slowdown:

Another strategy is more immigration. We have gone in the other direction in recent years, but immigration policy reforms keyed to the needs of the economy may be easier to sell to a skeptical public than an expanded version of the status quo.

However, Galston warns, “Getting America back to faster growth will take resources and focus. But if growth remains slow, Mr. Biden’s honorable effort to improve the lives of working- and middle-class families may end up hobbled by the well-known difficulties of zero-sum politics.”