So the S&P has finally bitten the bullet and downgraded US federal debt to AA+ from its forever rating as AAA. While this signals that according to the S&P US Treasuries are no longer the least-risky investments, what surprises me is the reaction of the markets.
So far, since the rating change was announced after US market hours on Friday evening, only one stock exchange has traded – the one in Saudi Arabia, and that has lost about 5%. While it can be argued that it is an extension of severe drops in the markets elsewhere in the second half of last week, at least a part of the drop can be explained by the US debt downgrade. Now, when markets elsewhere open tomorrow after the weekend, we can expect a similar bloodbath, with the biggest drop to be expected in the US markets.
Now, the whole purpose of ratings was supposed to be a quick indicator to lenders about credit risk of lending to a particular entity, and help them with marking up their loan rates appropriately. It was basically outsourcing and centralization of the creditworthiness process, so that each lender need not do the whole due diligence himself. You can argue in favour of ratings as a logical extension of Division of Labour. If lending is akin to making shoes, you can think of rating agencies analogous to leather tanners, to save each shoe maker the job of tanning the leather himself.
However, over the course of time, there have been two consequences. The first was dealt with sufficiently during the global crisis of 2008. That it is the debt issuer who pays for the ratings. It clearly points out to an agency problem, especially when the “debt issuers” were dodgy SPVs set up to create CDOs. The second is about ratings being brought into the regulatory ambit. The biggest culprit, if I’ve done my homework right, in this regard was the much-acclaimed Basel II norms for capital requirements in banking, which tied up capital requirements to the ratings of the loans that the banks had given out. This had disastrous consequences with respect to the mortgage crisis, but I’ll not touch upon that here.
What this rating-based regulation has done is to take away the wisdom of crowds in pricing the debt issued by a particular issuer. Normally, the way stock and bond prices work is by way of wisdom of crowds, since they represent the aggregate information possessed by all market participants. Different participants have different assumptions, and at each instant (or tick), they all come together in the form of one “market clearing price”.
In the absence of ratings, the cost of debt would be decided by the markets, with (figuratively) each participant doing his own analysis on the issuer’s creditworthiness and then deciding upon an interest yield that he is willing to accept to lend out to this issuer. Now, however, with ratings linked to capital requirements, the equation completely changes. If the rating of the debt increases, for the same amount of capital, the cap on the amount the banker can lend to this particular issuer jumps. And that means he is willing to accept a lower yield on the debt itself (think about it in terms of leverage).
Whereas in the absence of ratings, the full information known to all market participants would go into the price of debt, the presence of ratings and their role in regulation prevents all this information flowing out to the market in terms of the price of debt. And thus the actual health of the issuer cannot be logically determined by its bond price alone – which is a measure that is continuously updated (every tick, as we say it). And that prevents free flow of information, which results in gross mispricing, and large losses when mistakes are discovered.
I don’t have anything against ratings per se. I think they are a good mechanism for a lay investor to get an estimate of the credit risk of lending to a particular issuer. What has made ratings dangerous, though, is its link to banking regulation. The sooner that gets dismantled the better it is to prevent future crises.