In the case of liquidity, the shortcomings of our analytical tools are magnified by the difficulty of measuring leverage or identifying potential concentrations in the financial system. This has always been challenging, but the growth in the overall size of private pools of capital and the degree of embedded leverage that exists in many derivative instruments makes this more challenging today. When market liquidity and funding seem abundant, this is likely to be observable in things we can measure, like interest rates and credit spreads. And when liquidity ebbs, the effect is conspicuous in a range of observable market prices and volumes. But we do not have, and probably never will have, a set of indicators that offers the promise of predicting when liquidity conditions will reverse, or when markets are particularly vulnerable to a more acute decline in liquidity. In this sense, liquidity is like confidence. And, like confidence, liquidity plays a critical role both in establishing the conditions than can lead to a financial shock, and in determining whether that shock becomes acute, threatening broader damage to the functioning of financial and credit markets. What role can policy play in reducing the vulnerability of markets to this type of dynamic? Of course, central banks have a range of instruments they can use in the event of a crisis. By injecting liquidity into the system, and thus strengthening confidence, they can reduce the risk that temporary liquidity problems will result in default by otherwise solvent institutions, or damage to the payment system or credit process.

And yet many of the observations made about liquidity and market conditions over recent years have potential implications for monetary policy. Changes in risk premia, the level of asset prices, credit spreads, and interest rates, and in realized and expected volatility of asset prices – these can all affect the pace at which overall demand grows, and can therefore potentially affect future inflation. In discharging their responsibilities for the maintenance of price stability, central bankers need to be eclectic in looking at a range of different ways of measuring the stance of monetary policy, and its effects on the future path of growth and inflation. No indicators of liquidity or overall financial conditions provide a ready guide to judgments about monetary policy. But all these indicators merit careful attention, and they strengthen the argument against narrow or mechanistic approaches to thinking about the monetary and broader economic outlook. BIS Review 19/2007  3  Ultimately, though, ex ante judgments about leverage, concentrations and liquidity risk will continue to prove elusive. Our principal focus should therefore be not in the search for the capacity to preemptively diffuse conditions of excess leverage or liquidity, but in improving the capacity of the core of the financial system to withstand shocks and on mitigating the impact of those shocks. And, as always, central banks need to stand prepared to make appropriate monetary policy adjustments if changes in financial conditions would otherwise threaten the achievement of the goals of price stability and sustainable economic growth. Thank you.