The Young and the Restless If you rely on teenage workers, you may have noticed there's a shortage. What's going on?

Successfully employing teenagers helped Rob Nagel grow his Point Pleasant Beach, New Jersey-based business, Surf Taco, from one restaurant in 2001 to seven today. "They're the foundation," says Nagel, 37. "They're on the front lines taking orders, giving the customers food, connecting with the customers. Overall, they're responsible for whether I'm successful or not." The bad news for entrepreneurs like Nagel is that fewer teenagers work these days. The labor participation rate for 16- to 19-year-olds dropped to a low of 41.3 percent in 2007, according to the Bureau of Labor Statistics. That's down more than 10 percent from 1990, the first year teen labor rates began falling from a 1989 peak of 55.9 percent.

More emphasis on school, especially summer school, is the most commonly cited reason for the trend, says Mitra Toossi, a Bureau of Labor Statistics economist. However, she adds that labor participation rates for nonstudents have fallen as well, making the decline in teen workers even more mysterious--but it's a fact that entrepreneurs must face nonetheless.