Republicans, who control Congress but not the agencies that interpret and execute legislation, appear frustrated with the course of economic policy. They want the Fed to retreat more quickly from its stimulus campaign and to ease some of the restrictions that a Democrat-controlled Congress imposed on the financial industry after its 2008 collapse.
Ms. Yellen, for her part, pushed back more strongly than at past hearings, sometimes speaking over her questioners to make a point. She defended the Fed’s actions and warned against proposals to constrain its independence.
The hearing opened with a sharp exchange between Ms. Yellen and Jeb Hensarling, the Texas Republican who is chairman of the Financial Services Committee.
Mr. Hensarling backs legislation requiring the Fed to adopt a mechanical rule for setting its benchmark short-term interest rate. Such a rule would have limited the stimulus campaign the Fed has undertaken since the Great Recession.
He quoted a snippet of Ms. Yellen’s remarks at a 1995 Fed meeting at which she praised rules that mechanically dictate how the central bank should balance the sometimes-divergent priorities of moderate inflation and minimal unemployment. That, he quoted her as saying, “is what sensible central banks do.”
He then asked Ms. Yellen, “Do you no longer believe that a rules-based policy like the Taylor Rule is what sensible central banks do?” The rule is a formula written by the Stanford economist John Taylor that specifies interest rates based on inflation and the gap between actual and potential economic output.
But the context of that 1995 quote is important. Ms. Yellen was then pushing the Fed to pay more attention to job growth, and she was expressing a preference for rules that considered unemployment and inflation, as opposed to rules focused solely on the pace of inflation.
That, she said at the time, “is an example of the type of hybrid rule that would be preferable in my view, if we wanted a rule.”
She continued, “I think the Greenspan Fed has done very well by following such a rule, and I think that is what sensible central banks do.”
The Yellen Fed regards job growth as its priority, a transformation so complete that hewing to a Taylor-style rule actually would curb the Fed’s stimulus campaign. Ms. Yellen has said in other forums that she sees rules as useful reference tools, but that policy should be shaped by circumstances.
On Wednesday, pressed by Mr. Hensarling, she responded sharply.
“I don’t believe that the Fed should chain itself to any mechanical rule,” she said. “I did not believe that in 1995. I do not believe it now.”
Democrats argue that Mr. Hensarling’s proposal is an attempt by Congress to meddle in monetary policy.
“I think it’s important to have transparency but not at the expense of the independence of the Fed,” said Representative Al Green, a Texas Democrat.
Representative Scott Garrett, a New Jersey Republican, said in turn that Congress had intended to shield the Fed from political pressure “to juice the economy,” while in the current situation, Republicans were seeking to curb its stimulus campaign.
Like Ms. Yellen, he suggested that circumstances had changed and that the rules should adapt.