The most notable thing about the first-ever news conference of the Federal Reserve chairman, Ben S. Bernanke, last week was what wasn't discussed: banking regulation.

We hardly need more evidence that the most powerful banking regulator in the world, one that just became even more powerful after financial reform was passed, is also the least examined. Mr. Bernanke's opening remarks were about monetary policy and the economy. When he answered questions, he repeatedly referred to the Fed's "dual mandate" -- to keep inflation low and stable and to maintain full employment for the economy.

But that's not the Federal Reserve's true dual mandate. The Fed is indeed the steward of the economy, but it also has to regulate the financial system, making sure banks are safe and sound.

In the years before the financial crisis, the Fed was a miserable failure in that role, a creature of the banks, not a watchdog. The news conference was an opportunity for Mr. Bernanke to demonstrate what the Fed had learned from the crisis about banking oversight. After all, a collapsed financial system does spectacular damage to an economy.

There's more to discuss about this now than ever. Under the giant Dodd-Frank package, the Fed was given an expanded regulatory role. The new consumer financial products regulator is housed within the central bank. The Fed also now officially oversees investment banks, which it had to rescue during the crisis. Congress broadened the Fed's remit to cover nonfinancial institutions deemed "systemically important." Congress created a new role, the "vice chairman of supervision," to raise the prominence and importance of its responsibility. (It remains unfilled.) Perhaps most important, the Federal Reserve is supposed to play a major role in taking over big banks that fail.

Banking supervision has always been something of a backwater at the Fed. Within the institution, the sexy stuff is monetary policy. That's where most of the resources and attention goes. The chairman and the board spend a disproportionate amount of their time on it, and monetary policy expertise largely dictates the selection of board members. Many question that mind-set.

"Either expressly or implicitly, the Fed permeates every part of the Dodd-Frank reform," says Dennis Kelleher, the chairman of Better Markets, a new Washington advocacy group that aims to be a Wall Street watchdog. "Yet there is no indication that the leadership of Fed understands or is undertaking its new role as systemic risk regulator. It's not on the mind of the Fed chairman."

Without much public comment, the Fed is making critical decisions about the banks today. It just ran a round of stress tests for the banking system in which most banks came up smelling like roses.

Most big banks were allowed to pay dividends and pay back the government's Troubled Asset Relief Program money. Yet the economy is weaker than the Fed expected and the real estate market, which makes up the bulk of banks' exposure, is having a second downturn.

What gives the Fed so much confidence that the banks are properly valuing their assets and are adequately capitalized?

For a brief moment back in 2009, it was actually considered as bizarre to give the Fed more power. Christopher Dodd, then the chairman of the Senate Banking Committee, proposed creating a new financial regulatory infrastructure, stripping the Fed of its mandate.

Sadly, the bill was so dead on arrival it wasn't clear if even Mr. Dodd supported the Dodd bill. Nonetheless, removing banking regulation from the Fed's umbrella would have some clear advantages. Monetary policy is a pretty hard job. It might make some sense to split off regulation just to ease the burden.

And monetary policy can be in conflict with banking regulation. A central bank might prefer to shore up investor confidence and move on from a financial crisis without taking punitive action against wrongdoers, thinking that aggressive action might undermine faith in the system. Sound familiar to anyone?

Mr. Bernanke's news conference was also supposed to be a step toward realizing the Fed's new commitment to "transparency."

That's certainly welcome, but it has only gone so far. Congress repeatedly asked for more information on extraordinary actions taken by the Fed during the financial crisis, but was met initially with stonewalling. The central bank fought a lawsuit initiated by Bloomberg News to release data on what kinds of securities it bought during the financial crisis and from whom. When it lost and was finally forced to release the information, it did so in a fashion that it made assimilating the information difficult.

Earlier this year, when the Fed conducted its second round of bank stress tests, it made less information public than it had in the first round in 2009.

"Regulation needs accountability and transparency, and the Fed is just not set up to be accountable or transparent," says Mike Konczal, a fellow at the Roosevelt Institute, a liberal think tank focused on financial matters.

The sight of a Fed chairman answering reporters' questions in declarative English certainly was a departure from tradition. On Thursday, Bernanke is giving a speech on banking regulation. Let's hope that brings a comparable approach to regulation, which is ultimately far more significant.