Kennedy's undercover revelations. Green also interviewed Georgia State Prosecutor Dan Duke, whom he reported as denying having worked with Kennedy as closely as the latter had claimed. "Duke agreed that Kennedy 'got inside of some [Klan] meetings' but openly disputed Kennedy's dramatized account of their relationship. "'None of that happened,' [Duke] told Green", according to Freakonomics authors Stephen J. Dubner and Steven D. Levitt in their New York Times Magazine column of January 8, 2006. On the other hand, Peggy Bulger—the then-head of the American Folklife Center of the Library of Congress, who wrote her Ph.D. dissertation on Kennedy and interviewed him extensively—stated that when she interviewed Duke, "Duke laughed about the way The Klan Unmasked was written. But he added that Kennedy 'didn't do it all, but he did plenty.'" In the same column, Levitt and Dubner also quote Jim Clark, a professor at the University of Central Florida and co-author of a PBS television documentary based on Green's book, as saying that "[Kennedy] built a national reputation on many things that didn't happen". Jim Clark and Ben Green collaborated on the script of Freedom Never Dies: The Story of Harry T. Moore, based on Green's book and partially funded by the Freedom Forum. In a letter to Kennedy dated July 27, 1946, Georgia Governor Ellis Arnall wrote: 'You have my permission to quote me as making the following observation: Documentary evidence uncovered by Stetson Kennedy has facilitated Georgia's prosecution of the Ku Klux Klan.'" Dubner and Levitt had included a favorable summary of Kennedy's anti-Klan activities with special emphasis on the events recounted in I Rode with the Ku Klux Klan in the 2005 edition of their bestselling book. In the revised 2006 edition, after being contacted by Green, they retracted their earlier admiration, claiming that they had been "hoodwinked". The allegations in their retraction were swiftly repeated by the business journal Forbes in a review of the revised edition of Freakonomics: "It turns out that Kennedy doesn't quite live up to his own legend. In fact, he had exaggerated his story for decades and credited himself with actions taken by other people". Green's insinuations are contested by scholars, who emphasize that Kennedy never concealed that he had protected his colleagues' identities and maintain that Green either misread or did not really read the material at the Schomburg Center. Bulger maintains that Kennedy was always candid with her