Claudio Borio of the Bank of International Settlements is one of the most interesting and original economists of the day. A key innovation of his is the concept of the financial cycle. The idea is that the excess elasticity of the financial sector has dramatic consequences for real activity. Specifically, the supply of credit to the real economy is much more elastic than macroeconomic models have hitherto assumed or would be justified by macroeconomic fundamentals. In good times credit is plentiful and even very dicey borrowers can obtain credit quite cheaply. In difficult times even worthy borrowers find it hard to secure credit.
In order to empirically capture this boom-and-bust cycle, Borio and others developed a measure that uses filtering techniques. The idea is to isolate medium frequency movements in key indicators: credit-to-GDP ratio, total credit to the private sector, and property prices. Borio showed that the comovement of these indicators captures national financial cycles for a number of countries.
Technically: Borio uses a bandpass filter to isolate cycles with length ranging from 8 to 30 years in these three variables and averages them to obtain the financial cycle. Figure 1 displays Borio’s financial cycle for the United States.
I recomputed Borio’s financial cycle with more recent data. Figure 2 displays the US financial cycle from 1976-2015. We see that the financial cycle has turned since Borio calculated it.
US housing has always been a leading indicator of economic activity. Housing-finance is the primary channel through which the excess elasticity of the financial sector propagates to real activity. In what follows, we will see that a single metric of housing-finance, namely mortgage credit-to-gdp, captures the comovement of the components of the US financial cycle quite well. Figure 3 displays raw and detrended US mortgage credit-to-GDP. We can see the extraordinary boom in the run-up to the Great Financial Crisis. Figure 4 displays filtered US mortgage credit-to-GDP from 1951-2016 (using the same bandpass filter).
The US housing-finance cycle has become increasingly coupled to credit-to-GDP (Figure 5). It has long been coupled to property prices (Figure 6) and has become increasingly synchronized with the raw credit cycle (Figure 7).
Figure 8 displays the comovement of the US financial cycle and the US housing-finance cycle as measured by mortgage credit-to-gdp. We can observe three closed financial cycles that can be identified either by the three peaks or the four troughs. Mortgage credit-to-GDP (the US housing-finance cycle) barely rose in the first. Then there was a discernible but mild boom in mortgage lending during the late-1980s financial boom. But in the financial boom of the 2000s the two were phase-locked; so to speak. Note the increasing amplitude of both the cycles and the rigidity of the comovement in the last cycle. The past twenty years have witnessed a coupling of the two cycles.*
What explains the coupling of the financial and housing-finance cycles? One word: Securitization. Basically, the extraordinary amplitude of the financial cycle in the lead up to the Great Financial Crisis was the result of shadow lending. Figure 9, 10, and 11 show the contributions of banks and credit unions, US housing-finance agencies (“Agency MBS”), and shadow banks (“Private-label MBS”) respectively. Shadow lending accounted for 90% of the increase in mortgage credit-to-GDP during the housing-finance boom of 2003-2007.
Shadow banks here refers to finance companies, ABS issuers, and mortgage real-estate investment trusts (M-REITS), which are essentially artificial firms created by Wall Street to warehouse the raw material (mortgages) used to manufacture financial assets. Thus, securitization brought expanding dealer balance sheet capacity to the housing market and thereby amplified the US housing-finance cycle.
An interesting question for future research is whether housing-finance cycles are synchronous with financial cycles more generally. That is, is this an American peculiarity or is it true of other countries as well? Another open important question is how Borio’s financial cycle relates to Rey’s global financial cycle which is defined in terms of the comovement of global asset prices.
*We know from Rognlie’s work that the growing share of capital income in total income is explained almost entirely by capital gains on real-estate. That’s a third closely-related cycle.