Last October I noted that health-care and social-assistance positions had accounted for 64 percent of metro-Baltimore's job growth over the previous five years. In recent months the medical industry has carried even more of the burden. For March through May, Baltimore and its surrounding counties added 15,100 jobs, according to the Bureau of Labor Statistics. All but 3,000 came in health care. That's a stunning number, and it suggests that without the medical business metro Baltimore would be close to recession.

Business Week economist Michael Mandel, whose September story on the outperformance of health-care jobs on a national basis gave me the idea for last fall's column, has an update on his blog, which shows a similar pattern. His chart shows the gap between national growth in health-care jobs compared with growth in non-health-care jobs.

The health care sector is growing so fast, people joke, that eventually it will take up 100 percent of GDP and we'll all be working as doctors taking care of other doctors.