"The malign effect of high private debt"

The euro crisis: Debtors' prison at The Economist:

The malign effect of high private debt becomes apparent in the busts that follow credit-driven booms. Households that have borrowed too much in relation to their income trim their spending, the main component of GDP. Overleveraged firms avoid investing and concentrate on shrinking their balance-sheets by paying off loans. As bad debts erode their capital, banks become more reluctant to lend. These adverse trends reinforce each other, increasing the overall drag on growth.