Banca d’Italia

  • 01 Feb 2013 at 12:12 PM

Banks May Have Manipulated Euribor Out Of Modesty

The Libor scandal’s little brother, the Euribor scandal, is different from the Libor scandal in one important way. With Libor, banks are asked where they can borrow, and so if they can borrow at 2.5% and submit 2.4% then they’re lying. With Euribor, banks are asked where a prime bank can borrow, and so if they can borrow at 2.5% and submit 2.4% then … I mean, then who knows? Maybe they’re not prime? What’s a prime bank? This imprecision made Euribor impossible to manipulate, for some shady tautological meaning of “impossible to manipulate,” and so everyone felt very clever about avoiding scandals until they didn’t.

So when Libor rates were kept artificially low in 2007-2008, as banks tried to avoid seeming weak by submitting high rates: that was fraud. But when Euribor rates were kept artificially low, that was defensible. The intuition would be “well, last year we could all borrow at 3%, this year most of us can borrow at 4%, but we don’t look as prime as we used to. The best of us can still borrow at 3%, so Euribor = 3%.” That’s the intuition behind this amusing Banca d’Italia working paper by Marco Taboga:

Euribor rates are averages of survey responses by banks that are asked the following question: what is the interest rate that, to the best of your knowledge, a prime bank would charge another prime bank on an unsecured loan? The keyword in this question is “prime bank”. Before the crisis started, the concept of prime bank was probably rather unambiguous: there were dozens of large and internationally active banks that enjoyed AAA ratings and had tiny CDS premia (around or below ten basis points); any one of these banks would be easily recognized as a prime bank. During the crisis, however, most of these banks experienced deteriorations in their credit ratings and surges in their credit spreads. Which of them are still to be considered prime? In the absence of a standard de…finition of prime bank, this is a question that calls for quite a bit of subjective judgement. Therefore, it is conceivable that after 2007 Euribor rates might have been infl‡uenced also by changes in the survey respondents’’ perception of what a prime bank is. This paper provides empirical evidence in favor of this hypothesis.

The empirical evidence is more suggestive than definitive, and the effects are more visible post-2008 than during the crisis, but still. Here’s the picture: Read more »