The latest issue of Bloomberg Businessweek features an article (not yet posted online) that examines the need to boost human capital. Among the more interesting observations are those provided by Harold Sirkin.

Harold Sirkin, senior partner at Boston Consulting Group, places less value than [Harvard economist Lawrence] Katz does on four-year college degrees as a means of increasing the stock of human capital. “We need more vocational education,” he says. “Taking on more [student] debt isn’t worth it for everyone. Some people are better at working with their hands and building things. We may have reached a point where skilled manufacturing workers are becoming scarce.” That, says Sirkin, explains why some plumbers earn more than accountants. The share of young people with vocational degrees has been falling since the 1990s, and it kept dropping during the recession.

The human capital imparted in school can waste away if newly minted graduates can’t find work. Unemployment among young college graduates peaked at about 7 percent in 2011. It has since fallen to 5 percent. Yet according to the Federal Reserve Bank of New York, 46 percent of recent college graduates are working jobs that don’t require a B.A.

One suspects that none of this information surprises George Leef, who has argued for years that college is oversold.