Behavioral Game Theory

It is a year since Facebook launched shares on the Nasdaq. They were launched at $38 per share and now stand at a lowly $26. Anyone who bought a share would have lost 30% of their money.    At first sight this looks like a classic example of the winners curse. The winers curse captures the idea that the winner of an auction often loses money. IPOs (initial public offerings) are a textbook example of this. Here's the basic logic: If you ask 1000 investors to put a value on Facebook then the average valuation will probably be about right. But, shares are not sold to average investors. They are sold to the investors willing to pay the most. So, what really matters are the valuations of the most optimstic investors. And while the average investor will get the value about right, the most optimistic investors will not. They will overvalue the company and consequently pay too much. This is the winners curse: the investors who 'win the auction' to get Facebook shares would have

Earlier this week it the headlines that NICE (the National Institute for Health and Care Excellence) were recommending midwives use a carbon monoxide test to verify whether expectant mothers were smoking. Suitable fury from smokers followed. The proposal, however, is based on pretty sound economics.     The relationship between a child and parent is a principal-agent relationship. The basic idea of any such relationship is that a principal 'employs' an agent to do a 'job' for her. Its fine to interpret 'employs' and 'job' very loosely. In this case we can think of the unborn child as employing the mother to protect her growth and development. Clearly it is in the best interests of the child that the mother quit smoking, eat healthily etc. The mother, however, has different incentives. And, there were lots of mothers I heard on the radio this week determined to carry on smoking regardless. This is an example of a moral hazard problem: The agent, in thi

One of the big problems with US health care is the large number of uninsured people. A lack of insurance is costly for the state given that someone has to pick up the bill for all necessary treatment on uninsured patients. And its costly for society given that ill health can cause personal bankruptcy for anyone uninsured.    To fix the problem you need to know what is causing it. There are three basic causes. In looking through these its useful to have the following figure to hand. On the horizontal axis we plot the publicly observable health of the person, which might include things like weight, age, illness in the family etc. These are things the insurance company will take into account when assessing risk. On the vertical axis we plot the privately known health of the person, which also takes into account things like diet and exercise. These are things the insurance company would like to know but cannot, only the person knows. Each dot in the figure is a particular person. Most peo