May 29 (Bloomberg) — There are growing concerns that the regulatory bodies overseeing the financial sector are incapable of understanding, preventing or even properly investigating excessive risk taking that threatens to ruin the economy.

This issue was raised before the 2008 financial crisis and received more attention during the debate that led to the 2010 Dodd-Frank financial-reform law. Some tweaks were made in various parts of the regulatory apparatus, including the governance of the Federal Reserve Bank of New York, to reduce the influence of Wall Street.

In light of the $2 billion-and-counting trading losses at JPMorgan Chase & Co., the issue is back on the table. If anything, the key points have been sharpened both by what we know and don’t know about JPMorgan’s losses. It is time to consider establishing the equivalent of a National Transportation Safety Board for the financial sector, along the lines suggested by Eric Fielding, Andrew W. Lo and Jian Helen Yang. (Andrew Lo is my colleague at the MIT Sloan School of Management.)

In 2008, many things went wrong to create a true systemic crisis. The Financial Crisis Inquiry Commission spent a great deal of time poring over the details; in the end its conclusions split along party lines. In my assessment, deregulation allowed big financial companies to take on and mismanage excessive risks. They blew themselves up at great cost to the economy, and then received arguably the most generous bailout in history.

I blame the regulators and the banks, and the ways in which the latter captured the hearts and minds of the former (as well as politicians of both parties). Other people, particularly those who like such firms, disagree — and prefer to put the entire onus on the regulators.

The JPMorgan trading losses of 2012 are much more specific and focused. We know that something went badly wrong in a high- profile trading unit, staffed with people who were considered to be the best in the business. We know that Jamie Dimon, the chief executive officer, approved in general what was happening, yet appears not to have been informed about key decisions.

We don’t know the exact nature of the initial mistake or mistakes. We don’t know the details of reporting within the JPMorgan management structure. And we also don’t know what Dimon knew and when he knew it. There are press accounts on all these points — with some stories appearing to contain more or less guidance from JPMorgan’s public-relations team.

In essence, a serious accident occurred at JPMorgan. Or we might call it a “near miss” in terms of systemic implications. Major banks don’t fail in benign periods, and this isn’t the worst quarter in recent memory, nor the worst we are likely to face in the near future. (I’m thinking of a rolling series of likely debacles in the euro area.)

It is in the public interest to have a proper, independent investigation of the losses at JPMorgan. But here we run into a number of practical and political difficulties.

First, the obvious parties to conduct an investigation are also the regulators and supervisors of JPMorgan — and thus face a potential conflict of interest. Would the Securities and Exchange Commission, the Commodity Futures Trading Commission, the Office of the Comptroller of the Currency or the Federal Reserve really want to uncover and explain what they previously overlooked?

The Federal Bureau of Investigation has launched a probe, but its focus is presumably on whether to bring charges, rather than to figure out how to make the financial system safer. The Office of Financial Research, established by Dodd-Frank to monitor financial risk in the larger picture, so far has had no discernible effect.

Second, Dimon has the best possible political connections, including at the White House, where one of his former executives, Bill Daley, was until recently the chief of staff. Dimon also sits on the board of the Federal Reserve Bank of New York, a supervisor of large banks and the source of expertise on financial markets within the Federal Reserve system.

There is an active debate in and around official circles about whether Dimon’s position on the New York Fed creates the perception of a conflict of interest, or worse, the reality. Even Treasury Secretary Timothy Geithner suggested recently that Dimon should resign from that role. This is striking given that Geithner isn’t known to be unfriendly to very large banks.

If the CEO of an airplane manufacturer or a major airline sat on the NTSB board, would that make you more or less concerned about the safety of air travel? The board is a federal agency charged solely with investigating transportation accidents. Its members are appointed by the president, subject to confirmation by the Senate. Board members can’t be executives or employees of airline or other transportation-related companies. They are also not allowed to have any financial interest in such companies. (All these details and more are in the paper by Fielding, Lo and Yang.)

At the same time, the board members have long and relevant work experience. Their biographies are impressive. They have substantial political, regulatory, industry and practical experience (at least three are pilots, but I’m also impressed that the chairman is licensed to drive a school bus). One board member is an expert on human fatigue.

In most parts of U.S. public life, we care greatly about governance. This makes sense, given that the U.S.’s legal tradition is partly based on a long-standing and well-founded suspicion that strong executives can behave in an irresponsible and socially damaging manner. That was, of course, the problem the Founding Fathers had with King George III — and a perspective that motivated and informed the Constitutional Convention of 1787.

The board is a small agency (about 400 employees). Its area of expertise is disaster investigations. It also consults widely with all relevant parties after a crash or similar event, including with the people who built and operated the relevant systems. But there are clear rules regarding transparency for both the reporting of facts and deliberation of what happened (again, see Fielding, Lo and Yang for the details).

We need finance to run a modern economy, just as we need transportation. Finance has become more complex and more prone to major disasters; just ask JPMorgan shareholders. We should learn from accidents and mistakes and figure out how to make the system safer.

The point isn’t to eliminate risk from the financial sector, air travel or our lives; that is impossible and a fool’s errand. But we should better understand those risks and how to control them. When the supposedly best risk managers on Wall Street suddenly announce billions of dollars in unexpected losses, we need to know exactly what happened and why.

(Simon Johnson, a professor at the MIT Sloan School of Management as well as a senior fellow at the Peterson Institute for International Economics, is a co-author of “White House Burning: The Founding Fathers, Our National Debt, and Why It Matters to You.” The opinions expressed are his own.)