If the committee members agree on a decision that is acceptable for all of the different prevailing assumptions of the transmission mechanism, this could prevent monetary policy decisions which are optimal only in one specific model, but lead to negative results if another mechanism prevails.
In order to determine such a robust policy rule, we have to take two decisions: The first is on the set of models which should be taken into account. And the second is how to weigh the results these models  1  McCalllum, B. (1997) „Comment“ in : Bernanke, B.S. and Rotemberg, J.J. (Eds. ), NBER Macroeconomics Annual, 1997. The MIT Press.