For teenagers, a summer job is a rite of passage. In the past several months, the teen unemployment rate dipped below 18 percent—a big improvement, even if it’s still triple the rate for the general population. Most teens aren’t counted in the unemployment rate because they aren’t bothering to look for work. As recently as 2000, more than half of teenagers were in the workforce, as measured by the the labor force participation rate for 16- to 19-year-olds.