For many Americans, the financial crisis, and the recession it spawned, have been devastating -- jobs, homes, savings lost. Understandably, many people are calling for change. Yet change needs to be about creating a system that works better, not just differently. As a nation, our challenge is to design a system of financial oversight that will embody the lessons of the past two years and provide a robust framework for preventing future crises and the economic damage they cause.

These matters are complex, and Congress is still in the midst of considering how best to reform financial regulation. I am concerned, however, that a number of the legislative proposals being circulated would significantly reduce the capacity of the Federal Reserve to perform its core functions....