Like many students, Steve Vonderweidt hoped that a master's degree in business administration would open doors to a new job with a higher paycheck.

But now, about eight months after receiving his M.B.A. from the University of Louisville, Mr. Vonderweidt, 36 years old, hasn't been able to find a job in the private sector, and continues to work as an administrator at a social-service agency that helps Louisville residents obtain food stamps, health care and other assistance. He is saddled with about $75,000 in student-loan debt