How LIBOR Impacts Financial Models and Why the Scandal Matters

Jul 9, 2012Mike Konczal

If we can't rely on the accuracy of basic measurements used to set loan prices, we can't respond effectively to brewing financial crises.

Matt Taibbi asks why nobody is freaking out about the LIBOR scandal, Robert Reich calls it the scandal of all scandals, and Dylan Matthews has a great explainer of the whole thing here. Abigail Field has more at Reality Check.

This can be confusing stuff, so I want to go through a very simple example of how this impacts the markets. Here's a basic equation for the price of a loan:

The rate of a loan consists of adding the "risk-free" rate to a risk-premium. If either the risk-free rate or risk-premium goes up, then the price of a loan goes up. If you are a particularly risky borrower, you will pay more for a loan. This is because your risk-premium, compared to other borrowers, is higher, and that is added into your loan rate. If the risk-free rate is 3 percent and your risk of not paying back a mortgage requires a 2 percent premium, then your mortgage rate is 5 percent. If your risk of not paying back unsecured debt on a credit card requires an 8 percent premium, then your interest rate on your credit card is 11 percent.

More complicated models include more types of risk-premia and other things, but this basic approach is how financial markets work. They all need a measure of what money costs independent of the risks associated with any specific loan. As a result, all the most complicated models have this "risk-free" rate at their core.

Now think of some of the scandals and controversies over recent loan pricing. Here's a great Washington Post piece by Ylan Mui on African American homeowners scarred by the subprime implosion. There are cases where people with the same risk profiles were given different interest rates. Here's a report from EPI by Algernon Austin arguing that African Americans and Latinos with the same credit risks as whites were charged a higher total interest rate for mortgages even though the risk-free rate and their risk-premium rate should have been the same. The data implies that an additional, illegitimate "+ race" was added to the equation above.

There's also debates about what is appropriate to add to the risk-premium equation. The FTC alleged that credit card companies were using charges for marriage counseling or massage parlors to increase the risk-premium, and thus the total rate. Some would argue that, from the credit risk modeling point-of-view, these are appropriate measures to hedge against divorce; others would say that it looks like a cheap excuse to jack up the total rate using the risk-premium part of the equation as an excuse.

But those issues focus on how to price risk and what the total rate should look like. Running underneath all of these loans is what the "risk-free" rate should be. And by manipulating that rate, which forms the core of any financial model of how to price a loan, you manipulate every loan. Digging through some old financial engineering textbooks, it's amusing how many mathematical cartwheels are done to try and get an edge on the movement of LIBOR. Sadly. one can't model the dynamic of making an internal phone call and asking to please manipulate the numbers.

Now let's build out from a very simple model of a financial instrument to one of the more complicated ones -- the Black-Scholes PDE for pricing options and derivatives:

There's a lot of stuff going on in this equation which you can learn about here. But there's one variable you should catch. That "r" in the equation is the risk-free rate, which is usually LIBOR. One of the things Black-Scholes does is create a framework for understanding options and derivatives as owning pieces of the underlying object along with some cash, and getting the price of a derivative by understanding what it would mean to manipulate those two items. The cash in this framework, a crucial part, has its value determined by LIBOR. Which, as many are pointing out, implicates the gigantic derivatives market in this scandal.

Implicating the derivatives market makes it clear why this matters to the market. But what about the role this scandal played in the financial crisis? This brings me to part of Karl Smith's argument for why this scandal doesn't matter much. On Up with Chris Hayes he argued that both parts of the allegations shouldn't get us too upset, and in particular that the second allegation, that Barclays systemically manipulated its LIBOR rates downward (perhaps with the approval of regulators) to make it seem like it was healthier than it was, is a good thing. Why? Because it made the financial system seem healthier than it was, which was important to prevent a collapse.

In two follow-up posts (I, II) Smith clarifies his response. Smith argues that since the central banks were facing a financial crisis of epic proportions, one that would hurt many people, banks manipulating LIBOR helped keep that crisis at bay, which is a great thing. I think Smith has a theory I'm not following in which the only problem the banks had in 2008 was insufficient monetary policy, and not the fact that these banks were sitting on hundreds of billions of dollars in toxic loans that were causing a repo market bank run combined with an opaque over-the-counter derivatives system designed to induce counterparty risk in a crisis.

But the reason it matters is because that tactic can't work forever. You can manipulate prices and juke government stress tests and otherwise lie to make people believe your bank's balance-sheet is healthier than it is, but eventually that system is going to collapse. And, crucially, if the primary objective is "delay," then when the crisis actually hits, it hits in an overwhelming way with no plausible way to fairly allocate losses or take other actions.

As a side-note, if Smith agrees with manipulating LIBOR to look healthier, then he must really support the actions the Federal Reserve Bank of New York was taking in March 2008 to juke Lehman Brother's stress tests: "The FRBNY developed two new stress scenarios: 'Bear Stearns' and 'Bear Stearns Light.' Lehman failed both tests. The FRBNY then developed a new set of assumptions for an additional round of stress tests, which Lehman also failed. However, Lehman ran stress tests of its own, modeled on similar assumptions, and passed." Thank god that prevented an out-of-nowhere collapse that totally surprised the entire market!

The "TED Spread" is the difference between LIBOR and U.S. Government debt, and many used it in 2008 to track the financial crisis in real time (here's Krugman with "My Friend TED" from the time). Pushing LIBOR down makes the TED Spread look better. This looking healthier than it should meant that there was less pressure by regulators and legislators to find ways to allow these firms to fail, and that the most obvious way of dealing with the crisis was with a mass bailout. If you really want to deal with the crisis, you should affect either end of it that the price is reflecting, by either making the banks healthier or making sure we can deal with the failure.

The possibility that the regulators were in on it further clarifies the "protect the health of the largest banks at all costs" approach, one that squeezes every last bit of blood out of our turnip housing market and creates mass unemployment through a balance-sheet recession. And even if they weren't, that means that future measures to adeqately monitor the health of the banks through disclosures and market information might also be manipulated without (or even with) serious jail time or penalties.

This, by Smith, is wrong: "To my knowledge no one takes out an adjustable rate mortgage saying, 'what I really want is for my mortgage rate to reflect the level of panic in the global financial system should there by a once in 75 year crisis.' No, what everyone thinks is that they are getting the rate set by Federal Reserve and the Bank of England."

No, if that was the case there would be no use for LIBOR, and people would just use those rates. As Nemo summarizes in a great post on LIBOR from his bond series from years ago, the people pricing any loans at LIBOR want the pricing of a systemic credit crisis in their model. As Nemo says, "It is impossible to overstate how fundamental LIBOR is to the bond market." These prices are supposed to mean something, and the ability to add that information is a crucial reason it has shown up in so many pricing models. It would be a better world if those numbers weren't being manipulated to the advantage of inside traders.

Mike Konczal is a Fellow at the Roosevelt Institute.

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