Cowen isn't the kind of partisan that Krugman portrays in his op eds. (For that matter, I doubt Krugman really is, either.)

Some quickly googled examples of Cowen agreeing with or praising Krugman:

http://www.marginalrevolution.com/marginalrevolution/2010/04... http://www.marginalrevolution.com/marginalrevolution/2008/12... http://www.marginalrevolution.com/marginalrevolution/2006/03...

Many more examples can be found of partial agreement, e.g. http://www.marginalrevolution.com/marginalrevolution/2009/02... and http://www.marginalrevolution.com/marginalrevolution/2006/03...