Friday's grim labor report is the latest confirmation that our economy is not recovering. A loss of 131,000 jobs and a stagnant 9.5% unemployment rate are bad enough. But a deeper look—at the little-known civilian employment-population ratio—shows how hard it's going to be to pull out of our crisis, and why the Obama administration's policies are unlikely to do the job.

In contrast to the better-known unemployment rate, which measures the percentage of working-age Americans who are actively seeking jobs but do not have one,...