JW Mason — The Dynamics of Household Debt

Changes in debt-income ratios can be attributed to primary borrowing, interest rates, growth, and inflation. In a new working paper, we apply such a decomposition to the evolution of U.S. household debt.  This shows that changes in borrowing behavior has played a smaller role in the growth of household leverage than is widely believed. Rather, most of the increase can be explained in terms of “Fisher dynamics” — the mechanical result of higher interest rates and lower inflation after 1980. Bringing leverage back down will similarly require contributions from factors other than reduced borrowing.

Read it at The Rorty Bomb
JW Mason: The Dynamics of Household Debt

by J. W. Mason
(h/t Mark Thoma)

We draw two main conclusions. First, as a historical matter, you cannot understand the changes in private sector leverage over the 20th century without explicitly accounting for debt dynamics. The tendency to treat changes in debt ratios as necessarily the result in changes in borrowing behavior obscures the most important factors in the evolution of leverage. Second, going forward, it seems unlikely that households can sustain large enough primary deficits to reduce or even stabilize leverage. Even the very large surpluses of 2006-2011 would not have brought down leverage at all in the absence of the upsurge in defaults; and in the absence of large federal deficits and an improving trade balance the outcome would have been even worse since reductions in household expenditure would have reduced aggregate income.  As a practical matter, it seems clear that, just as the rise in leverage was not the result of more borrowing, any reduction in leverage will not come about through less borrowing. To substantially reduce household debt will require some combination of financial repression to hold interest rates below growth rates for an extended period, and larger-scale and more systematic debt write-downs.