However, new regulation may affect the magnitude of these affects, and the size of the market-based financial sector may end up being smaller after the crisis. In Europe, the commercial banks dominate the financial sector. 18  Kohn (2006, 2008) specifies three conditions that should be fulfilled for central banks to take “extra action” to deal with a possible asset-price bubble: “First, policymakers must be able to identify bubbles in a timely fashion with reasonable confidence. Second, a somewhat tighter monetary policy must have a high probability that it will help to check at least some of the speculative activity. And third, the expected improvement in future economic performance that would result from the curtailment of the bubble must be sufficiently great.” He concludes, also in 2008 and after thorough considerations, that those conditions would rarely be met. See also Kohn (2009). BIS Review 16/2010  9  In particular, if there is evidence of rapidly-rising house prices and mortgage loans, and these developments are deemed to be unsustainable and a possible bubble, there are much more effective instruments than policy rates. Restrictions on loan-to-value ratios and minimum mortgages and requirements of realistic cash-flow calculations for house buyers with realistic interest rates are much more effective in putting a break on possible unsustainable developments than a rise in the policy rates. In particular, more transparency about future policy rates, in the form a policy-rate path published by the central bank, may help in providing realistic information about future interest rates.

14  Nyberg (2010) provides more discussion of macroprudential regulation and regulation reform. BIS Review 16/2010  7  significant social costs. I find it helpful to conceptually distinguish financial-stability policy from monetary policy. Different economic policies and policy areas, such as fiscal policy, labor market policy, structural policies to improve competition, etc., can be distinguished according to their objectives, the policy instruments that are suitable for achieving the objectives, and the authority or authorities controlling the instruments and responsible for achieving the objectives. Monetary policy in the form of flexible inflation targeting has the objective of stabilizing both inflation around the inflation target and resource utilization around a normal level. The suitable instruments are under normal circumstances the policy rate and communication, including possibly a published policy-rate path and a forecast of inflation and the real economy. In times of crisis, as we have seen during the current crisis, other more unconventional instruments can be used, such as fixed-rate lending at longer maturities, asset purchases and foreign-exchange intervention to prevent currency appreciation. The authority responsible for monetary policy is typically the central bank. Financial-stability policy has the objective of maintaining or promoting financial stability. The available instruments are under normal circumstances supervision, regulation and financialstability reports with analyses and leading indicators that may provide early warnings of stability threats. In times of crisis, there are instruments such as lending of last resort, variable-rate lending at longer maturities, special resolution regimes for financial firms in trouble, government capital injections and so forth.