In December, there were a bit more than 209.1 million people of working age in the United States, according to government numbers. In March, the latest numbers show, there were a little bit less than 208.6 million. That decline of half a million people isn’t a big deal, but it’s a sign of a bigger demographic problem the U.S. is facing.

In a few years, the working-age population will begin falling, and it will keep falling for the foreseeable future. While this happens, baby boomers will continue to retire, and so the worker-to-dependent ratio, already at all-time highs, will accelerate. Unless automation can fully fill the gap, the result will be shortages, high inflation, and lower quality.