26/7/17: Credit booms, busts and the real costs of debt bubbles

A new BIS Working Paper (No 645) titled “Accounting for debt service: the painful legacy of credit booms” by Mathias Drehmann, Mikael Juselius and Anton Korinek (June 2017 http://www.bis.org/publ/work645.pdf) provides a very detailed analysis of the impact of new borrowing by households on future debt service costs and, via the latter, on the economy at large, including the probability of future debt crises.

According to the top level findings: “When taking on new debt, borrowers increase their spending power in the present but commit to a pre-specified future path of debt service, consisting of interest payments and amortizations. In the presence of long-term debt, keeping track of debt service explains why credit-related expansions are systematically followed by downturns several years later.” In other words, quite naturally, taking on debt today triggers repayments that peak with some time in the future. The growth, peaking and subsequent decline in debt service costs (repayments) triggers a real economic response (reducing future savings, consumption, investment, etc). In other words, with a lag of a few years, current debt take up leads to real economic consequences.

The authors proceed to describe the “lead-lag relationship between new borrowing and debt service” to establish “empirically that it provides a systematic transmission channel whereby credit expansions lead to future output losses and higher probability of financial crisis.”

How bad are the real effects of debt?

From theoretical point of view, “when new borrowing is auto-correlated [or put simply, when today’s new debt uptake is correlated positively with future debt levels] and debt is long term - features that are present in the real world - we demonstrate two systematic lead-lag relationships”:

• “debt service peaks at a well-specified interval after the peak in new borrowing. The lag increases both in the maturity of debt and the degree of auto-correlation of new borrowing. The reason is that debt service is a function of the stock of debt outstanding, which continues to grow even after the peak in new borrowing.” It is worth noting a well-known fact that in some forms of debt, minimum required repayment levels of debt servicing (contractual provisions in, say, credit cards debt) is associated with automatically increasing debt levels into the future.

• “net cash flows from lenders to borrowers reach their maximum before the peak in new borrowing and turn negative before the end of the credit boom, since the positive cash flow from new borrowing is increasingly offset by the negative cash flows from rising debt service.”

Using a panel of 17 countries from 1980 to 2015, the paper “empirically confirm the dynamic patterns identified in the accounting framework… We show that new borrowing is strongly auto-correlated over an interval of six years. It is also positively correlated with future debt service over the following ten years. In the data, peaks in debt service occur on average four years after peaks in new borrowing.” In other words, credit booms have negative legacy some 16 years past the peak of new debt uptake, so if we go back to the origins of the Global Financial Crisis, European household debts new uptake peaked at around 2008, while for the U.S. that marker was around 2007. The credit bust, therefore, should run sometime into 2022-2023. In Japan’s case, peak household new debt uptake was back in around 1988-1989, with adverse effects of that credit boom now into their 27 years duration.

When it comes to assessing the implications of credit booms for the real economy, the authors establish three key findings:

1) “…new household borrowing has a clear positive impact, and its counterpart, debt service, a significantly negative impact on output growth, both
of which last for several years. Together with the lead-lag relationship between new borrowing and debt service this implies that credit booms have a significantly positive output effect in the short run, which reverses and turns into a significantly negative output effect in the medium run, at a horizon of five to seven years.”

2) “…we demonstrate that most of the negative medium-run output effects of new borrowing in the data are driven by predictable future debt service effects.” The authors note that these results are in line with well-established literature on negative impact of credit / debt overhangs, including “the negative medium-run effect of new borrowing on growth is documented e.g. by Mian and Sufi (2014), Mian et al. (2013, 2017) and Lombardi et al. (2016). Claessens et al. (2012), Jorda et al. (2013), and Krishnamurthy and Muir (2016) document a link between credit booms and deeper recessions.” In other words, contrary to popular view that ‘debt doesn’t matter’, debt does matter and has severe and long term costs.

3) “…we also show that debt service is the main channel through which new borrowing affects the probability of financial crises. Consistent with a recent literature that has documented that debt growth is an early warning indicator for financial crises, we find that new borrowing increases the likelihood of financial crises in the medium run. Debt service, on the other hand, negatively affects the likelihood of crises in the short turn.”

In fact, increases in probability of the future crisis are “nearly fully” accounted for by “the negative effects of the future debt service generated by an increase in new borrowing”.

The findings are “robust to the inclusion of range of control variables as well as changes in sample and specification. Our baseline regressions control for interest rates and wealth effects. The results do not change when we control for additional macro factors, including credit spreads, productivity, net worth, lending standards, banking sector provisions and GDP forecasts, nor when we consider sub-samples of the data, e.g. a sample leaving out the Great Recession, or allow for time fixed effects. And despite at most 35 years of data, the relationships even hold at the country level.”

So we can cut the usual arguments that “this time” or “in this place” things will be different. Credit booms are costly, painful and long term.