REAL estate bubbles have burst before, without bringing such trouble to the financial system. What is distinctive today is the drying up of market liquidity  the inability to buy and sell financial assets  caused by a lack of good information about asset values. The American economy is suffering from an old conundrum: that liquidity is there when you don’t need it, but missing when you do. The results have been a form of financial gridlock.

If you think that traders have been well informed of late, take another look at the wild path of Bear Stearns shares: A year ago, the stock was selling for $170 a share. At the close on March 14, just before the deal by which Bear Stearns was to be bought by JPMorgan Chase, Bear had a book value of $80 a share  and a share price of $30. The JPMorgan transaction, arranged two days later, valued the company at about $2 a share. Since then, the shares have been trading above $2, which in part reflects the possibility of the deal breaking up.

Every step of the way, the pricing of the stock has surprised the market  and yet Bear Stearns is a firm with a lengthy history, not an Internet start-up or a biotech whose value is based on a new but untried wonder drug.

To understand the depths of the current crisis, let’s go back to an apparently unrelated episode in economic thought: the socialist calculation debate. Starting in the 1920s, Ludwig von Mises, the leader of the so-called Austrian School of Economics, charged that socialism was unable to engage in rational economic calculation. Without market prices, he reasoned, no one knows how much economic resources are worth.