Behold the dangers of contaminated collateral [updated]

Yale University’s Gary Gorton and Guillermo Ordoñez have a new working paper out on the role of collateral in financial crises. This may not pass for exciting news in some places but FT Alphaville is not like other places. Gorton is renowned for his work on shadow banking and wrote an excellent short primer on the recent crisis.

(Update: He’s also, as our commenters point out, the man behind some of the AIG’s risk-management models. Take that as you will, we still think there are some interesting insights in the paper.)

The paper, “Collateral Crises”, uses complicated mathematics we don’t understand want to discuss at this point. But don’t let that put you off: it has some important insights for those interested in the role of information and collateral in the financial system.

First, a very important caveat: the below refers to a model. The empirical evidence presented in the paper is labelled “Very Preliminary and Incomplete” so consider the ideas below as educated musings rather than empirical statements.

The hypothesis is a neat one and although the authors readily admit it’s just one way of looking at recent troubles, it’s an interesting way of thinking about how the crisis hit when it hit.

The argument runs something like this: short-term private funding markets such as money markets or interbank markets work by dealing in “information-insensitive debt”. In other words, there’s buying and selling without anyone worried about adverse selection. Collateral is put down and — assuming it’s AAA — no questions are asked. These ideas have been suggested before (such as here) but this paper is the first to look at its macroeconomic implications.

In particular, it uses this micro model to explain how small shocks can translate into big events. To understand the professors’ logic it’s useful to grasp their version of financial crisis events (our emphasis):

Financial crises are hard to explain without resorting to large shocks. But, the recent crisis, for example, was not the result of a large shock. The Financial Crisis Inquiry Commission (FCIC) Report (2011) noted that with respect to subprime mortgages: ”Overall, for 2005 to 2007 vintage tranches of mortgage-backed securities originally rated triple-A, despite the mass downgrades, only about 10% of Alt-A and 4% of subprime securities had been ’materially impaired’-meaning that losses were imminent or had already been suffered-by the end of 2009” (p. 228-29). Park (2011) calculates the realized principal losses on the $1.9 trillion of AAA/Aaa-rated subprime bonds issued between 2004 and 2007 to be 17 basis points as of February 2011. The subprime shock was not large. But, the crisis was large…

The authors hypothesise that when these types of collateral markets exist, no useful information is created because it’s too costly (at least for market participants in the short-term) to do so. Thus there’s no information that can help one distinguish between good and bad collateral — between Scandinavian government bonds, say, and AAA-rated sub-prime mortgage bonds.

Indeed, there’s more consumption and lending when there are no questions asked. The longer the boom continues, the more ignorance percolates and bad collateral gets into the system.

When information is not produced and the perceived quality of collateral is high enough, firms with good collateral can borrow, but in addition some firms with bad collateral can borrow. In fact, consumption is highest if there is never information production, because then all firms can borrow, regardless of their true collateral quality. The credit boom increases consumption because more and more firms receive 3financing and produce output. In our setting opacity can dominate transparency and the economy can enjoy a blissful ignorance.

Here’s the problem. The bigger the lie, the harder the fall:

In this setting we introduce aggregate shocks that may decrease the perceived value of collateral in the economy. It is not the leverage per se that allows a small negative shock to have a large effect. The problem is that after a credit boom, in which more and more firms borrow with debt backed by collateral of unknown type (but with high perceived quality), a negative aggregate shock affects more collateral than the same aggregate shock would affect when the credit boom was shorter or if the value of collateral was known. Hence, the size of the downturn depends on how long debt has been information-insensitive in the past.

Gorton and Ordoñez are not rubbishing the importance of leverage — indeed they’re sort of talking about leveraged opacity. But their original argument is that the sub-prime shock was not large and not in itself the cause of the subsequent fall-out. It was the overall reduction in perceived quality of collateral.

A negative aggregate shock reduces the perceived quality of all collateral. This may or may not trigger information production. If, given the shock, households have an incentive to learn the true quality of the collateral, firms may prefer to cut back on the amount borrowed to avoid costly information production, a credit constraint. Alternatively, information may be produced, in which case only firms with good collateral can borrow. In either case, output declines because the short-term debt is not as effective as before the shock in providing funds to firms.

There’s a fair bit to critique here and not just to state the obvious point that credit rating agencies are supposed to provide the sort of information found useful by market participants. Leverage also probably does matter “per se”: it affects the pace in which margin calls come in and funding crises hit. Moreover any notion of intent is missing here — opacity serves some interests more than others.

Still, there are some interesting ideas here and we’ll be cockahoop to see some empirical evidence about the importance of not being able to separate good and bad collateral.

The big sort, rather than the big short.

Update II: Not for the first time, the comments section on an FT Alphaville post are more enlightening than the main text. Scroll down for more, and do contact rob2.7 if you can speak complex mathematics.

Related links:
Shadow banking – from Giffen goods to Triffin troubles – FT Alphaville
Regulating the shadow banking system – Marginal Revolution
Interview with Gary Gorton – Minneapolis Fed
Gary Gorton on Financial Crises – Five Books Interviews

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