08/22/2012 07:00 pm ET Updated Oct 22, 2012

Should You Trust Academic Celebrities?

The recent row between Niall Ferguson and Paul Krugman has a certain "knights on horseback" quality to it. The political battle lines are impossible to miss: Ferguson wrote an article criticizing Obama's economic record, and Krugman called him out on his data. What separates this from any other op-ed showdown is that each of the participants comes armed with a long line of academic credentials: Ferguson is a historian at Harvard, and Krugman is a Nobel laureate economist at Princeton.

Of course, academics disagree for a living. Much of what we do consists of forming and defending ideas. But here we have a case of high-powered academics going to the media to publicly weigh in on political issues just before an election. So who should we believe?

The first thing to understand about academic celebrities is that the role they play in public life is very different from what they do professionally. Academics train for years to develop expertise on very specific topics. When we see academics on television or in print, they are often commenting on areas outside of their specific training. This is particularly the case for well-known figures such as theoretical physicist Micho Kaku, who is often called upon to interpret all things scientific. I am not deriding him for this -- communicating difficult science to a general audience is an extremely difficult task, and a genuine service to the public. But he would no doubt be the last person to call himself an "expert" on some of the topics he discusses on CNN.

The second is that a disagreement between Ferguson and Krugman is not a proxy battle between Harvard and Princeton. Universities are hotbeds of disagreement. That's what they are for. Short of promoting something like hate speech, a professor will not be cut loose from a university just for advocating an opinion that is unpleasant or unpopular. Berkeley is known for leaning left, yet also counts among its professors John Yoo -- one of the architects of the Bush administration's legal justification for the "enhanced interrogation" of enemy combatants.

Of course academic celebrity has its own rewards for the individuals and the institutions that hire them. At a basic level fame, even notoriety, sells books. The very famous members of our profession will earn a great deal more from publishing royalties than they do from salary. And the salaries can be quite high. University presidents will pay handsomely for star faculty, including people that are not that well regarded by their peers. The reason is that students will flock to universities that have famous professors, even if public renown is not necessarily matched by respect within the field. Famous academics don't even have to be real -- after the release of the first Indiana Jones film in 1982, the University of Chicago was reportedly swamped with applications to its archeology program.

The point is that academic celebrities are a bit like expert witnesses in a courtroom -- they cover the full spectrum of personalities and abilities and motivations. So by all means listen, but always be critical. A good professor will always tell students to be critical and form their own conclusions. A good public academic would expect the same treatment.

As always, I welcome comments on this blog, and will respond to specific questions on my personal webpage.