 Which of the following most likely happened to Krugman after these letters?
Krugman's Life of Brian Where it all started: Paul Krugman's "The Legend of Arthur." 1) Krugman claims that my opening sentence--"In a way, Bill Gates's current troubles with the Justice Department grew out of an economics seminar that took place thirteen years ago, at Harvard's John F. Kennedy School of Government"--is "pure fiction." (As Krugman notes, one reason for this was technical, not ideological. 3) Pace Krugman, I also did not claim that Arthur bears principal responsibility for the rediscovery of increasing returns by economists in the 1970s and 1980s. 4) Krugman appears to suggest that I made up some quotes, a charge that, if it came from a more objective source, I would consider to be a serious matter. After Krugman's article appeared, the Santa Fe professor called me to say that he still recalled the meetings in question as I described them. Krugman, as he admits, wasn't present at either of the meetings. 5) For a man who takes his own cogitations extremely seriously, Krugman is remarkably cavalier about attributing motives and beliefs to others. Evidently, Krugman felt four years ago that Arthur's contribution was important enough to merit a prominent mention in his book. Now, he dismisses the same work, saying it "didn't tell me anything that I didn't already know." Cassidy Paul Krugman replies to John Cassidy: I think that David Warsh's 1994 in the Boston Globe says it all.
 Krugman lost credibility among his colleagues.
 Krugman wrote an official apology to the writers.  Krugman wrote another book about increasing returns.  Krugman quit writing in newspapers.  Krugman lost credibility among his colleagues.