EXPERTISE. Political Theory links to a Robert Samuelson column looking at the role of the academy in the production of journalists. Samuelson is unimpressed with Columbia President Lee Bollinger's desire to have journalists credentialed in the manner of lawyers and physicians. Bollinger's motivation comes in part, according to Samuelson, from a fear of concentration of media ownership. As if additional credentialing ever served to break down entry barriers. It's also rather funny to hear anyone in the Ivies complaining about concentration: usually they benefit by it, as in accounting for their share of the grant money, their page production in leading journals, their graduates placed at research universities.