U.S. student loan debt has almost doubled over the past five years, the congressional Joint Economic Committee revealed on June 18. Its report puts the volume just below $1 trillion in the first quarter of this year, up from $550 billion at the end of 2007. Two-thirds of recent graduates are carrying an average of more than $27,000 in student loans, and the burden on new borrowers will swell even higher unless Congress blocks a rise in interest on federal Stafford loans to 6.8 percent from 3.4 percent starting July 1. Bankrolling their college education would cost $4,500 more for students who borrow the maximum on those loans if no action is taken before then. "Allowing the interest rate on subsidized Stafford loans to double at a time when the government's cost of borrowing is so low undermines the public policy objective of providing affordable loans to students," according to the report.