Their research helped the Bank of Japan to adopt its 2 percent inflation target in 2013. So, research is essential and economics is essential to research. But that is not the whole story. Monetary policy should be grounded in sound economic principles and data, but applying these principles and gathering data require certain skills.
Surely that will lead to dilemmas and conflicts of interest if, say, the supervisors ascertain the number of sovereign bonds held by troubled banks. An increase in interest rates could put pressure on the prices of these bonds and thereby on the banks. The ECB would have a conflict and could postpone an interest rate increase that may be warranted from a monetary perspective.