Alabama has the right idea. It is the execution which is faulty.

The state recently announced that it will begin charging state employees if they are obese and fail to improve their health. Obese people generate $1,748 more in annual medical expenses than smaller people, according to one official, and if employees don't show progress toward better health within a year, they will pay $25 a month for health insurance which is otherwise free. Alabama already charges employees who smoke.

It's hard to fault the state's rationale. Like smoking, obesity has been linked to a multitude of health problems such as cardiovascular disease, hypertension, diabetes and joint failure. All are expensive to fix after the fact, and all are preventable. This knowledge is common, and there is no reason why people should pay the entire cost for those who knew the consequences yet still chose unhealthy practices. Insurance pools were designed to spread risk, not to provide an unconditional safety net that encourages poor choices.

In trying to do the right thing, however, Alabama is going about it incorrectly.

First there is the use of punishment rather than incentive. It's hard to give people a break on insurance which is already free, but Alabama has other options to provide an incentive. Employees could receive an extra day or two off or a bonus; research by a health care information firm has shown that a payment of about $100 is a better incentive than time off and is enough to attract the interest of most people.

Second is the seeming rigidity of the rules. Employees will be screened for cholesterol, blood pressure and other measures health, but the charge will apply automatically to those with a body mass index greater than 35 (30 is the baseline for obesity) who fail to make progress. It is unclear whether there is any allowance for people who don't fit the rules - people whose weight is the result of some underlying health problem or drug, women who gained weight during pregnancy but haven't lost it immediately after giving birth, or people who are built on large frames but whose physiology gives them good health. There is much that we still do not understand about the human body, and it would be singularly unfair to penalize people simply for being big.

Then there is the need for the state to live its ideals because poor health can result from culture as much as individual choice. In a state which ranks second in the number of obese people, one must question whether the deep-fried foods characteristic of Southern cooking have also been banished from the plates of the state managers complaining about obesity.

Penalties can elicit strange behavior. People who are cooperative and productive can turn surly and slothful when they believe they are being unfairly treated. Impose a penalty, and people may pay it happily - sticking it to the man with one more french fry.