 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." I am reluctant to dignify his hatchet job with a lengthy reply, but some of his claims are so defamatory that they should be addressed, if only for the record. 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." Perhaps so, but in that case somebody should tell this to Joel Klein, the assistant attorney general in charge of the antitrust division. It was Klein's words, not those of Arthur, that prompted me to use Arthur in the lead of the story. (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. As Krugman notes, several scholars (himself included) who were working in the fields of game theory and international trade published articles incorporating increasing returns before Arthur did. Krugman apart, virtually every economist I have spoken to, including Daniel Rubinfeld, a former Berkeley professor who is now the chief economist at the Justice Department's antitrust division, told me this was the case. 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. The quotes in question came from Arthur, and they were based on his recollections of two meetings that he attended some years ago. 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. I presume this statement refers to a critical piece I wrote in 1996 about the direction that economic research, principally macroeconomic research, has taken over the past two decades. In response to that article, I received dozens of messages of appreciation from mainstream economists, including from two former presidents of the American Economic Association.
 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.