This has come up here before - why do listeners constantly hear the same "experts" on talk radio every week? People like Sylvain Charlebois, the so-called "Food Professor" or Michael Geist, a university expert on Canadian media? If you're a listener, you can probably come up with a lot of other similar names.

They all come from the world of academia, and one National Post critic accuses producers of the shows they appear on of being "unimaginative" and not finding new voices to comment on ongoing controversial topics. 

"In Canada there is no shortage of politicians, but when it comes to academics talking about politics the spotlight tends to fall on a few."

I can tell the author why the same people appear over and over - every producer has a sort of electronic Rolodex of dependable guests to turn to on a given subject. They're articulate, they know their stuff, they're fairly entertaining and when the phone rings, they almost always say yes. And they come on for free. 

That's something money literally can't buy and why they keep turning to them over and over.

But he's not wrong that a change of face or voice would be welcome occasionally, in place of the same voices on the same topics on the same stations.

Canada's unimaginative media can't get enough of these academics