If you offer people free booze, they will tend to take more than they need, if not more than is good for them. If you then tell them it’s not actually free, they will want a lot less.

This is worth bearing in mind when thinking about liquidity. A great many people have been spending a great deal of time worrying about bond market liquidity. But, mostly, they have been looking at the wrong end of the problem. They should be looking less at the supply of liquidity and more at demand.