With his leg injured in a recent skiing accident, Arnold Schwarzenegger, California's governor, this week announced a plan that could change the terms of America's health-care debate. The Republican in charge of the country's most populous state, where 6.5m people, almost one resident in five, lack medical insurance, said he wants to introduce universal health-care coverage.

His recipe is a combination of insurance-market reform, government subsidies and—most important—compulsion...

Although the details are still sketchy, Mr Schwarzenegger's plan is very like another pioneering health-care reform that was successfully championed by another Republican governor in a strongly Democratic state. In April 2006 Mitt Romney, then the governor of Massachusetts and now a leading Republican presidential candidate, agreed on a plan for universal health-care coverage with the state's Democratic legislature. It too made health insurance mandatory, and it also included insurance reform and subsidies.

Massachusetts, and now California, have the boldest plans...Could the states jump-start American health-care reform?..

A lot depends on whether the states' reforms actually appear to work. All eyes are on Massachusetts, since it is the first state actually to enact (rather than merely propose) comprehensive reform, particularly the mandatory purchase of insurance. From July 2007 every resident must have health insurance, or face a $1,000 fine...

Forcing everyone to buy insurance is probably the only way to avoid the “adverse selection” problem that plagues health-insurance markets. Younger workers in good health avoid buying coverage, leaving higher-risk people in the insurance pool, thus driving up premiums. And if the uninsured workers fall really ill, they become free-riders on the others, since hospitals are required to treat them at public expense: had they been treated earlier, they might have been cured more cheaply...

Maine and Vermont are both trying to insure all their citizens. Both have rejigged their insurance market for individuals and small businesses. Both are offering subsidies to poorer people. But neither compels anyone to buy insurance. Vermont's plan was introduced less than a year ago. But Maine's plan has been up and running since January 2005, and its results have been disappointing. According to Cristy Gallagher of the New America Foundation, a Washington, DC, think-tank, only 15,000 people have enrolled so far. The state is a long way from covering its 130,000 uninsured citizens, while the subsidies are proving costlier than expected...

For the complete article, please visit The Economist website.