How should monetary and regulatory policy be combined?
Part of the debate about monetary policy, even before the crisis, was whether the interest rate rule, implicit or explicit, should be extended to deal with asset prices. The crisis has added a number of candidates to the list, from leverage to measures of systemic risk. This seems like the wrong way of approaching the problem. The policy rate is a poor tool to deal with excess leverage, risk taking, or apparent deviations of asset prices from fundamentals. A higher policy rate also implies a larger output gap. Other instruments are at the policymaker’s disposal—call them cyclical regulatory tools. If leverage appears excessive, regulatory capital ratios can be increased; if liquidity appears too low, regulatory liquidity ratios can be introduced and, if needed, increased; to dampen housing prices, loan-to-value ratios can be decreased; to limit stock price increases, margin requirements can be increased. If monetary and regulatory tools are to be combined in this way, it follows that t
