"Has the U.S. created an 'education bubble' fueled by easy money and overborrowing by families desperate to pay rising tuition costs?" asks The Wall Street Journal. "Expect a hastily sputtered 'no way' from economists, university officials and student-lending specialists. They attach a high monetary value to academic degrees, no matter how fast tuition rises. But the student-loan market has been riddled with signs of trouble lately. Default rates are rising. Big-name lenders are pulling out or scaling back. And investors who used to snap up bonds backed by bundles of student loans have snapped their checkbooks shut. Runaway college expenses are straining many families' borrowing capacity. While some families can handle the load, others are starting to look like homeowners who bought too much house for their budgets. A key statistic to watch is the default rate on 'private' student loans."