The new issue of the BIS Quarterly Review carries some interesting empirical work on debt reduction after crises. The paper is here and the summary is:
Financial crises tend to be followed by a protracted period of debt reduction in the nonfinancial private sector. We find that a period of debt reduction followed 17 out of 20 systemic banking crises that were preceded by surges in credit. Debt/GDP ratios fell by an average of 38 percentage points, returning to approximately the levels seen before the increase. If history is any guide, we should expect to see a much more significant reduction in private sector debt, particularly of households, than has so far taken place after the recent crisis. The costs of this process in forgone output are difficult to pin down, but there are reasons to believe that they need not be high provided that the banking sector problems that led to the crisis are fixed.