The need for liquidity is a mantra among those who organise and regulate the financial system. To say that a proposal will damage liquidity more or less stops further discussion.
那些组织和监管金融系统的人士总把对流动性的需求挂在嘴边。如果说一项计划会破坏流动性，那么这项计划基本上就没有进一步讨论的必要了。
But what is liquidity? When I reviewed UK equity markets for the government last year, most participants told me liquidity was best judged by the spread – the difference between what it would cost to buy and sell the same share simultaneously. But since this is not a transaction anyone is likely to make, this indicator made little sense. Others regarded the volume of trading as a measure of liquidity; but this led to the circular argument that trading was good because it encouraged trading, a perspective relevant for those who own exchanges but not for anyone else.
但究竟什么是流动性？去年我为英国政府做股市评估时，大多数市场参与者告诉我，衡量流动性的最佳指标是价差——某只股票某一时刻的买价与卖价之差。但考虑到并不是所有人都会在某一时刻既买入又卖出某只股票，这一指标其实意义不大。其他人则把交易量作为衡量流动性的指标，但这导致了一个循环论证：这类交易之所以不错，是因为它促进交易。从交易所所有者的角度来说，这么说是合适的，但从其他人的角度来说则不然。
The quest for liquidity rests on an illusion. Banks tell their customers they can have their deposits back immediately, even though they could not if all did so at once. It is often suggested that this confidence trick makes banking unique – banks have a mysterious capacity to “create money”. But the same device is used in many other markets to create an appearance of availability that exceeds the underlying reality.
人们对流动性的追求建立在一个错误的观念之上。银行告诉客户，他们如果想取存款立刻就可以取出，尽管这一点在所有人都同时取款时是不可能做到的。常有人说，这种信心把戏让银行业显得与众不同——银行拥有一种“制造货币”的神秘力量。但同样的伎俩也在其他许多市场被使用，目的是制造一种可获得性超出真实水平的假象。