Poole cited the Fed's Aug. 9 statement that it would keep its main interest rate low through mid-2013, a date that has since been pushed back by the committee. The yield on the 10- year Treasury note fell to 2.11 percent on the day after the statement from 2.32 percent the day before.
In an April 20 speech, Poole said the announcement "seemed to come out of left" field. Plosser, who backs the idea of a policy rule, said that with 17 members, the FOMC may not be ready to reach a consensus.
"I suspect that the FOMC participants are not ready to agree on a specific policy rule or reaction function because they use different models," Plosser said in an April 12 speech.
Until they adopt a rule, Fed officials should agree on a set of economic variables that they would observe when setting policy, Plosser said.
"If we choose a consistent set of variables and systematically use them to describe our policy choices, the public will form more accurate judgments about the likely course of policy, thereby reducing uncertainty and promoting stability," Plosser said.
'Suite' of Rules
James Bullard, president of the Fed bank of St. Louis, told reporters after an April 16 speech that he determines the FOMC's best way forward by reviewing "a suite of policy rules" while focusing on the rate of economic growth.
The Chicago Fed's Charles Evans has suggested the Fed refrain from tightening policy until unemployment falls below 7 percent or inflation exceeds 3 percent.
"The Fed uses rules to provide a benchmark for policy discussions as opposed to a mechanical formula to run policy," said Mark Gertler, an economics professor at New York University who has co-written research with Bernanke.
"There are too many factors unknowable in advance to turn policy over to a mechanical rule," he said. "At the same time, I think laying out the basic criteria for when the Fed is likely to add or withdraw stimulus is useful."