Doctor Shortage by 2015 in the U.S.?

There is only one reason for there to be a shortage of anything: Prices are not allowed to adjust to market-clearing price levels.

So how can someone [though it is difficult to figure out who] forecast a shortage of physicians in the United States, as someone does in this article?

Since 1977, Harris says, the prestige the public assigns to medical doctors has slipped from 61% to 52%, and the nation may face a shortage of 85,000 to 200,000 doctors in 15 years.

[Link via Tyler Cowen at Marginal Revolution, "What are the most prestigious jobs?"]

Before you click on the comments to argue that barriers to entry can create a shortage, don't do it. Barriers to entry [e.g. via limited enrolments in medical schools] can reduce the supply, thus forcing the price up, but there will not be an excess of the quantity demanded over the quantity supplied unless prices are restricted.

So what does the article mean? That the writer expects gubmnts to impose wage controls on physicians? That demand will increase very rapidly due to an aging population but prices will not adjust very quickly? Or just that people will end up paying more than they want to pay, in part because of limitations on admissions to medical schools?