If the ongoing turmoil in the world’s financial markets has made anything clear, it’s that the list of things that can go wrong in those markets is a very long one. Month after month, it seems, another potentially disastrous problem rises to the surface. The latest looming crisis is the possible implosion of a group of companies called monoline insurers. If you haven’t heard of monoline insurers, don’t worry: until recently, few people, even on Wall Street, were all that interested in them. Yet their problems have become a serious threat to global markets. Rumors that monoline insurers, like M.B.I.A. and Ambac, were in serious trouble helped spark the vast market sell-off that prompted the Federal Reserve’s interest-rate cut two weeks ago, and, only a few days later, rumors of a government-orchestrated bailout of these companies set off a six-hundred-point rally in the Dow.

CHRISTOPH NIEMANN

Monoline insurers do a straightforward job: they insure securities—guaranteeing, for instance, that if a bond defaults they’ll cover the interest and the principal. Historically, this was a fairly sleepy business; these companies got their start by insuring municipal bonds, which rarely default, and initially they confined themselves to bonds with relatively predictable risks, which were easy to put a price on. Unfortunately, a sleepy, straightforward business wasn’t good enough for the insurers. Like everyone else in recent years, they wanted to cash in on the housing and lending boom. In order to expand, they started insuring the complex securities that Wall Street created by packaging mortgages, including subprime ones, for investors. This was a lucrative business—M.B.I.A.’s revenues rose nearly a hundred and forty per cent between 2001 and 2006—but it rested on a false assumption: that the insurers knew how risky these securities really were. They didn’t. Instead, they gravely underestimated how likely the loans were to go bad, which meant that they didn’t charge enough for the insurance they were offering, and didn’t put away enough to cover the claims. They’re now on the hook for tens of billions of dollars in potential losses, and some estimates suggest that they’ll need more than a hundred billion to restore themselves to health.

Obviously, this is bad news for the insurers—at one point, M.B.I.A.’s and Ambac’s stock prices were down more than ninety per cent from their all-time highs—but it’s also very dangerous for credit markets as a whole. This is because of a peculiar feature of bond insurance: insurers’ credit ratings get automatically applied to any bond they insure. M.B.I.A. and Ambac have enjoyed the highest rating possible, AAA. As a result, any bond they insured, no matter how junky, became an AAA security, which meant access to more investors and a generally lower interest rate. The problem is that this process works in reverse, too. If the insurers lose their AAA ratings—credit agencies have made clear that both companies are at risk of this, and one agency has already downgraded Ambac to AA—then the bonds they’ve insured will lose their ratings as well, which will leave investors holding billions upon billions in assets worth a lot less than they thought. That’s why so many people on Wall Street are pushing for a bailout for the insurers. It may be an abandonment of free-market principles, but no one has ever accused the Street of putting principle above profit.

Normally when companies make bad decisions and fail to deliver value, it’s just their workers and investors who suffer. But monoline insurers’ desire to grab as much new business as they could, risks be damned, quickly radiated across global markets and will have huge consequences for millions of people who have never heard of M.B.I.A. or Ambac. The situation illustrates a fundamental paradox of today’s financial system: it’s bigger than ever, but terrible decisions by just a few companies—not even very big companies, at that—can make the entire edifice totter.

In that sense, the potential collapse of monoline insurers looks like a classic example of what the sociologist Charles Perrow called a “normal accident.” In examining disasters like the Challenger explosion and the near-meltdown at Three Mile Island, Perrow argued that while the events were unforeseeable they were also, in some sense, inevitable, because of the complexity and the interconnectedness of the systems involved. When you have systems with lots of moving parts, he said, some of them are bound to fail. And if they are tightly linked to one another—as in our current financial system—then the failure of just a few parts cascades through the system. In essence, the more complicated and intertwined the system is, the smaller the margin of safety.

Today, as financial markets become ever more complex, these kinds of unanticipated ripple effects are more common—think of the havoc wrought a couple of weeks ago when the activities of one rogue French trader came to light. In the past thirty years, thanks to the combination of globalization, deregulation, and the increase in computing power, we have seen an explosion in financial innovation. This innovation has had all kinds of benefits—making cheap capital available to companies and individuals who previously couldn’t get it, allowing risk to be more efficiently allocated, and widening the range of potential investments. On a day-to-day level, it may even have lowered volatility in the markets and helped make the real economy more stable. The problem is that these improvements have been accompanied by more frequent systemic breakdowns. It may be that investors accept periodic disasters as a price worth paying for the innovations of modern finance, but now is probably not the best time to ask them about it. ♦