Throughout the financial crisis, one question has bubbled to the surface again and again: “Who’s to blame?” While many are pointing the finger at former executives like Stan O’Neal and Dick Fuld, others are targeting something a little more abstract: the models financial institutions use to calculate the risk in their portfolios.

A recent New York Times article chronicled the role that VaR (Value at Risk), the most widely used of these models, played in contributing to the crisis. Joe Nocera, the author of the article, summarizes how the model works: “If you have $50 million of weekly VaR, that means that over the course of the next week, there is a 99% chance that your portfolio won’t lose more than $50 million.”

The potential damage represented by the remaining 1%, however, is incalculable. And while events that trigger losses in this range don’t come along often, they do come along. The subprime crisis and subsequent credit crunch were extremely unlikely events; as such, they were just the type that models like VaR were ill equipped to anticipate.

Taking issue with the model is Professor Eric Schoenberg, who first expressed his frustration in a letter to the editor. “Relying on a faulty measure is fine,” Schoenberg says in an interview, “if the only person who suffers when that measure fails is you. But that’s not the way the system is set up. And unless people acknowledge that they basically are relying on a public utility to allow them to run their business — which very few investment banks are willing to acknowledge — it’s not an exercise in intellectual argument. It’s an exercise in power politics. It’s about what you can get away with.”

While Schoenberg admits that the issue of how much risk financial institutions should be allowed to take on is a difficult one, he believes that leverage lies at the heart of the matter. “In order to address the moral hazard problem, people have to have a lot more at risk themselves relative to what generalized risks they’re creating. There has to be a significant reduction in the amount of leverage we allow these institutions to have.”

Where do we go from here? “We must acknowledge that there is a fundamental disconnect between what makes sense for individuals and what makes sense for the group, and the only entity that can address what’s right for the group is the government,” Schoenberg says.

“Basically, this is the issue of free market fundamentalism, which is the idea that markets are best and any time the government intervenes it’s going to screw things up. Well, if you have that belief, you know, you’re going to have these things happen over and over and over again.”

Photo credit: Travel Aficionado