Don't read too much into the fact that he's a chairman of a department.  Plenty of departments are chaired by morons.  Plenty are chaired by brilliant people.  My old department's chairman was an excellent developmental economist.  (Most of his research deals with Africa.  He's not very involved in the traditional areas of the field, like business cycles and monetary theory.)  Unfortunately, becoming chairman of a department can sometimes be more of a political victory than an intellectual one.

Auburn University, for example, is a very Austrian-leaning department, even though Austrian economics is not followed by many economists, while Princeton was chaired by Ben Bernanke, a Keynesian, for a long time.  Bernanke also hired Krugman.  You'll find departments tend to become stacked with people of the same view, unfortunately.

As for coming to different conclusions, you can find the same problem among climate researchers, and God knows that statisticians love to tell all sorts of stories with data.  It's more a question of finding the economists who know what they're talking about.  That can be difficult, but it's certainly not impossible.

Conservatives want live babies so they can raise them to be dead soldiers. - George Carlin