27 September 2008

Mortgages and scale

Arnold Kling, who knows what he's talking about, says that the idea that mortgages will turn out to have a better return than their current market prices indicate is rubbish. In his view, the market prices are likely to accurately reflect the true value.

As far as I can see, that is unlikely. In a simplistic model, underpriced mortgages will be bought by investors who can make profits by holding them. But surely any such model assumes capital is plentiful relative to the assets under discussion. The crucial fact here is that, because of the past hideous underestimate of risk, the size of the mortgages held by institutions who shouldn't be holding them is, apparently, in the high hundreds of billions of dollars. Many other investors have felt they are a good long-term bet. But most of those investors have already bought as much as they can afford, or else are holding on for better bargains, knowing that there is no competition to bid the prices back up in the short term.

On that argument, a buy-up by the US government is indeed a profitable opportunity for it. I think it could be defended on those terms. If I were drawing it up, however, I would want it explicitly to aim at making a profit. I would set a fund of fixed size to buy assets, planned to ensure that some of them are left over, and then spend it over a shortish period buying whatever seemed to be most competitively priced. The aim would be to make profits, and hopefully do some general good in the process; not to save overexposed financial institutions at any cost.

Is this counter to my principles? Yes. I do not consider myself a "naive libertarian", in that I recognise that state intervention can be beneficial in some cases. However, I think that forgoing such benefits, by separation of economy and state, would be a better general policy than allowing fallible politicians to identify allegedly beneficial interventions. This intervention, even if beneficial, sets a horrific precedent, and will terribly undermine all free-market arguments for years to come. It could usher in an era of big government. That's why it should be opposed.

Indeed look at the converse. If it doesn't happen now, and the system survives with less damage than the proponents are claiming, what a valuable example it will be of how markets are able to adjust to the most severe problems.

26 September 2008

Washington Mutual

Since Washington Mutual, like Northern Rock, has now gone bust without owning securitized mortgage derivatives, can we please lose the idea that securitization was the problem. Mortgages were the problem.

Without securitization, the financial system would have been much more exposed, but it would have just been the retail banks, not brokerages like Bear and Lehman.

Also, if securitization has been done properly, and the brokerages had actually sold the securities they created, there would have been much less of a problem. All the loss would be carried by investors who were not leveraged and were risking funds they could afford to lose. I know I said that before, but now Tyler Cowen is saying it too (or at least approvingly quoting others who are).

Now it can be argued that, had the risk not been spread out by securitization, the problems of bad loans would have come to a head much sooner, and the total impact would therefore have been smaller. That might be true. It is totally equivalent to saying that if there was no regulation of financial institutions, the problems might have got obvious sooner and therefore have been smaller. True or not, it's a strange way of looking at things. Since nobody is using the John Adams seat-belt argument that regulation is the problem, then blaming securitization should be out of court as well.

24 September 2008

What was the problem?

Since I have claimed that the derivatives involved in the financial system problems were not too complicated, what was the real problem?

There are many candidates, too many to cover right now. The use of irrelevant statistics to justify risky holdings, as I mentioned before, was a large part of the problem. The government pressure to make more and cheaper loans to less creditworthy borrowers has been widely commented on, and may have contributed significantly, but can't excuse the banks' errors.

The actual error made by the banks was very simple - embarrassingly simple, really. They bought mortgages to securitize them. They split the securities into high-risk, medium-risk, and low-risk bits. They valued the bits and found that they were more valuable than the original mortgages, which meant the process was profitable to them. They sold the high-risk bits to speculators and the medium-risk bits to long-term investors. But they kept the low-risk bits. Thats it! That's the error!

Presumably, after they valued the low-risk bits, they found that nobody actually wanted to buy them at that valuation. What they should have done was price them down until people did want them, then re-evaluate the whole business on the basis of the actual market prices that they got for them. I have no idea whether that would have meant that securitization would have carried on or not. But either way, it would not have left the financial system dangerously exposed to the housing crash. At worst, it would have ended up as the "normal" sort of Wall St scandal - clever investment bankers sell a whole load of toxic crap to investors (see auction-rate, internet IPOs, etc. etc. etc.)

Why did the banks hang onto these investments, rather than sell them? I guess that they believed they were "really worth" pretty close to par value, and that buyers didn't want to buy them at that price just because they were uninformed. Also, because they were rated as so safe, the regulators were happy to consider them non-risky for the purposes of capital requirements. That was the regulators' biggest error. Because of course these two justifications contradict each other. If the securities can't be sold at their alleged "real value", then they are tying up the banks' capital, and should be counted as such.

(I'm surprised we haven't heard more about the mezzanine tranches that were sold to fund managers, pensions, insurance, etc. They were never seen as safe, so the bodies holding them could afford to take losses on them.)

It almost seems a shame that this whole crisis is caused by one such straightforward error. It ought to be something like "derivatives are too complex" or "regulators were subverted" or "government forced banks to make bad loans". It's a let-down that it was just "banks held one particular type of investment that it was never their business to hold, just as a by-product of one business line".

22 September 2008

Financial Complexity

I want just to grab one factoid out of the swirl of information and misinformation relevant to the current financial situation - the idea that the problems were caused by fiendishly complicated derivatives (see, e.g., here)

Horribly complex derivatives do exist: a "snowball", for example, "is a structured swap with a funding leg and a coupon stream whereby the coupon paid on a given date is given by the sum of a fraction of the coupon paid in the previous period plus an amount determined by the realization of the rate process in the coupon period itself"

However, while estimating the value of a snowball requires so much computer power that researchers are designing custom hardware and offloading computation onto graphics chips, the difficulty of valuing a derivative does not depend on the derivative itself being complex. The mortgage backed securities which are the most obvious cause of the current problem are actually quite straightforward. That doesn't make them easy to value.

The point of the complexity is in fact to make them easier to value. After all, no amount of differential calculus will tell you whether Mr Bloggs at number 11 will default on his mortgage, if you don't know whether he has a job, and what his credit card balance is, and whether house prices on his street are going up or down. If you have good statistics, however, you might have a decent stab at how much a thousand mortgages are worth, or how much the best 400 out of a thousand are worth.

That was the theory. It failed, not because of the complexity of the derivatives, or because of errors in the mathematics, but because the statistics were crap. Statistics collected over ten years during which house prices only ever went up were not of much use when prices started to fall. Statistics collected on mortgages originated by lenders with their own money cannot be used to accurately model mortgages originated by lenders working only for commission. Et cetera.

The other bugbear instruments in some commentary are the "weapons of financial mass destruction", credit default swaps. These are simpler still; just a guarantee by one party of a debt owed by another. The main problem with them is their very simplicity - rather than selling them on like securities, someone holding one would just create a new one to cancel it out. That's what makes it so difficult to sort things out when a participant like Lehman defaults - its net position is manageable, but that net consists of astronomical credits and debits that almost, but not quite, cancel each other out. If the CDSs were more sophisticated (with central clearing), the problems would be smaller.

I think that this New York Times piece is very good, except for the one point, that the difficulty of valuing a mortgage derivative is not due to its inherent complexity, but mostly just because it's made out of mortgages.