PHILADELPHIA -- At Society Hill Loan, a pawnshop in a middle-class neighborhood here, a steady rain fell outside as a fashionably dressed young man parked his Cadillac Escalade outside. Looking around warily, he came in to speak with Nat Leonard, co-owner of the store.

The visitor was a 29-year-old engineer who was laid off earlier this year from one of the local chemical companies. Since then, he's been cleaning planes at the airport for less than half the salary he was earning a year ago.

Now...