Yves Smith packs a powerful insight into an unassuming sentence:

Liquidity is not a virtue in and of itself unless it produces a benefit to the real economy.

Liquidity is often said to be the great lubricant of financial markets. Let's go with that metaphor for a moment. Yeah, baby, liquidity. It's high performance motor oil that turns hard metal to smooth silk and keeps the engine of capitalism firing on all cylinders! Pop the hood and pour that stuff in. Rub it onto the gears and axles, so nothing ever squeals, pops, or (God forbid) grinds to a halt. Slather it all over the tires, so that no friction comes between our purring metal machine and the sweet American road.

Ummm, wait a minute... Putting lubricant on the tires might not be such a great idea after all. Friction is precisely what tires need to do their jobs. Throw a lot of oil on the tires and, well, something bad might happen.

Similarly, in financial markets, we want liquidity at some times and in some places. But there are times and places where we want, even need (gasp!) illiquidity!

Illiquidity. That word is so ugly. What might be another word for the same phenomenon? How about "commitment"? When a person invests in something that is not very liquid, they are committed. They are necessarily betting on its fundamental value. Liquid securities can be bought or sold as a trend or a trade or a play for a greater fool. But if the thing you are buying can only be sold with a big haircut, you'd better hope for a really gigantic fool if you have no confidence in its underlying value. (Clever managers did find ways around this problem, but let's put principal/agent issues aside for the moment.) When financial markets are too liquid, everything looks like cash. Superfluous distinctions — like the economic meaning of the assets bought or sold — fall by the wayside. Sure, investors always prefer liquidity to illiquidity. An option to buy or sell quickly and cheaply is preferable to an option to buy or sell slowly and with large transaction costs. But just because investors like something doesn't mean that it's good. Investors like rainbows and ice cream and free money from taxpayers. But the rest of us prefer that investors make serious, informed decisions about what is and isn't of value, and that they be paid for evaluating and actually bearing risk, rather than artfully shifting it (or whining when it cannot be shifted, because omigawd-there-is-no-liquidity!). Of course there is a balance here, commitment is one thing but a ball and chain is another, if assets become too hard to buy or sell, the costs of financing genuinely useful enterprises would increase until even good risks are not borne at all. It's not that liquidity is a bad thing. It's a good thing of which there can too much.

But how much? Another word that should be attached to any conversation about liquidity is "accuracy". There is, in some sense, a "right" level of liquidity, defined by the uncertainty surrounding the present value of an assets future payoffs. We laud markets for "price discovery", their ability to distill complex economic facts into simple prices that put a value to unknowable future events. But we need markets to communicate the uncertainty surrounding those valuations as well. The depth-weighted spreads of assets whose values are nearly certain should be much narrower than those of assets whose payoffs cannot be accurately predicted. When that is not the case, it represents a market failure. The recently wide spreads on complex structured credits are not the crisis — those spreads accurately reflect the uncertainty surrounding what the instruments are actually worth. Nobody knows, so spreads should be wide. The real crisis was two years ago, when "oceans of liquidity" meant that whatever the underlying value of a thing, you could sell it quickly for near what you bought it, so spreads grew artificially narrow. Confidence is good only when confidence is merited. We need not only accurate prices, but accurate confidence intervals, accurate spreads, accurate levels of liquidity rather than simply more, more, more.