NY Times Runs Fourth Correction of Krugman

So the NY Times has now run their fourth correction of an editorial by former economist and current political hack Paul Krugman. But what do the regional papers, like the N&O, do? The N&O chooses to carry some Krugman columns, and while he is not as vile as Molly Ivins, almost every editorial is open to later corrections. Does the N&O have an obligation to run corrections as well? I would hope so, but I haven't seen any yet.
Paul Krugman