 Which of the following most likely happened to Krugman after these letters?
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. 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. Which brings me to Professor Krugman's letter, and my reply. Accordingly, I included a passage in Complexity in which Brian does indeed describe what others had done in the field--Paul Krugman among them.
 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.