Americans worked a median of 52 hours last year without pay. They’re called volunteers. Many organizations can’t survive without unpaid labor, and many people are glad to provide it. Sadly, though, data released Wednesday by the U.S. Bureau of Labor Statistics show that both the number of volunteers and the volunteer rate — the percentage of the population that volunteers — declined in 2007 from 2006. Volunteering also had fallen in 2006 from 2005. About 60.8 million Americans, age 16 and up, volunteered in 2007, compared with a high of 65.3 million in 2005. The proportion of that population that...