I consider myself center-left and I like Krugman a lot, but you can't deny he's just as biased as Cato/AEI (on the right), and the Brookings Institute (on the left). They are all biased. That being said, they are all reputable enough not to outright lie or distort. At worst they selectively omit, or their opinions/editorializations/analysis are wrong or speculative.