Banks are famous for being willing to lend only when you don’t need it. Like the guy who hands you an umbrella when it’s nice and sunny–only to take it back at the first sign of rain–banks are unwilling to extend credit when it’s needed to restore economic stability. Why? Because the system is designed to reward behavior that is bad for society and punish conduct which is good.

For example, when money was cheap and pentiful, anyone who could fog a mirror was granted mortgage financing. Lenders couldn’t write loans fast enough, and the ones who wrote them fastest and loosest earned the most. Then, when economic conditions turned sour and money was most needed to restore order in financial markets, lenders took it all away and pulled back. Which made things worse and perpetuated the cycle. Because banks are businesses, and businesses owe a duty to their stockholders to make as much money as legally possible, current law reinforces this behavior.

So like it or not, government has to step in when the best decision for business isn’t the best for society. An article in the LA Times explains why we should care about the takeover of the two mortgage giants Fannie Mae and Freddie Mac. Experts predict that government control of Fannie and Freddie will ensure a certain level of liquidity in mortgage financing, keeping money available for those who should be granted mortgages and supporting the housing markets. Right now, banks and other mortgage lenders have no downside–when times are good they can lend early and often–and rashly. Then, when the bad loans come back to bite, taxpayers are asked to shoulder the losses. So a company doing its duty by its shareholders is pretty much obligated to exploit this loophole. It needs to be closed so that taxpayers can get out of the mortgage business.