Levitt (above) is being sued by Lott (below) who believes his integrity is at stake.  Photography: Andreas Larsson

In December 1998, Chicago Mayor Richard M. Daley held a press conference to tout a new initiative against gun violence: the city had sued gun dealers for liability, much the way state governments sued the cigarette companies. The press conference, part of a U.S. Conference of Mayors meeting, featured several speakers and a video presentation, but a man in the audience, a fierce defender of the right to carry a gun, tried to interrupt the mayor with pointed questions. That was John R. Lott, then a visiting professor of economics at the University of Chicago and the recent author of More Guns, Less Crime, which argued that laws allowing private citizens to carry concealed guns resulted in sharp reductions in rates of violent crime.

On the U. of C. campus, some people found Lott's behavior that day unusual for an academic, and stories made the rounds that he had heckled the mayor until police took him from the room. Lott denies this account vigorously. In an e-mail recently, he said he had merely tried to ask Daley a couple of questions, but was shushed by mayoral aides because he was not a journalist. "I did not raise my hand again after that. After the questions, I met up with the CBS reporter [Mike Flannery] and we walked out of the building together. I was not removed by police."

In any case, the incident suggested that Lott would go to considerable lengths to promote and defend his point of view. That became acutely clear last April when he filed a defamation suit against a fellow economist and former colleague, Steven D. Levitt, coauthor of the blockbuster book Freakonomics. In the suit, filed in federal court in Chicago, Lott said that Levitt had attacked his "integrity and honesty" in Freakonomics and in a private e-mail message. "When a book sells over a million copies, this goes beyond a mere debate among academics," Lott has said in a blog posting.

John Lott   Photo: Courtesy of The American Enterprise Institute

Still, the case is rare-intellectual quarrels don't often end up in federal court-and it culminates an ongoing dispute between the two men, who knew each other at least casually at the U. of C. "I even had the pleasure of dining at his home with John, his wife, and their four [at the time] young boys," Levitt told me.

Ostensibly, the two men have a great deal in common. Lott, 48, and Levitt, 39, were both pioneers of econometrics, a discipline that uses statistics and computer software to examine how society actually works (a departure from the usual stuff of economics, such as unemployment rates and bond yields). Levitt brings econometrics to bear on outré questions: How much money do drug dealers really make? Do sumo wrestlers cheat? Do Chicago public school teachers cheat in reporting their students' scores on standardized tests? "The only things I'm really good at," Levitt has said, "really and honestly, are asking questions that people seem to find interesting and figuring out how to trick data into answering those questions."

One question Levitt asked has thrust him into a heated debate on crime and morality. National crime rates plunged suddenly in the 1990s-exactly one generation after the Supreme Court legalized abortions in 1973. In an argument first made in 1999 and repeated in Freakonomics, Levitt has asserted that abortions reduced the number of unwanted children, who tend to grow up to be criminals. Though Levitt takes pains to insist that this finding says nothing about whether abortion is morally right or wrong, both his conclusion and his scholarship have been roundly criticized.

One of the critics was Lott. As soon as Freakonomics appeared, Lott wrote a letter to The Wall Street Journal, calling the authors' abortion-and-crime theory "plausible" but contending, "if anything, the reverse is true. Their data had a serious error."

Levitt retorted in an online posting that Lott had coauthored a paper on abortion and crime "loaded with inaccurate claims, errors and statistical mistakes. . . . Virtually nothing in this paper is correct, and it is no coincidence that four years later it remains unpublished."

For his part, Lott also stirred controversy by examining crime in the United States, turning econometrics toward the question of whether gun-control laws really reduced violent crime. His conclusion-that gun-packing communities were safer-set off howls of protest from gun-control advocates. Critics attacked Lott's research as technically flawed if not bogus, and he has been defending himself against such charges ever since.

Lott has had to defend himself over an embarrassing gambit, too. In 2001, somebody named Mary Rosh began posting on online forums, gushing over Lott as a writer and teacher: "I had him for a PhD level empirical methods class when he taught at the Wharton School at the University of Pennsylvania back in the early 1990s, well before he gained national attention," Rosh wrote, for example, "and I have to say that he was the best professor I ever had." This was posted in, of all places, a chat room about the TV show The West Wing (an episode dealt with gun politics).

The writer with this high regard for John Lott turned out to be . . . John Lott. "Mary Rosh" was an alias derived from the first names of Lott's sons, Maxim, Ryan, Roger, and Sherwin. Julian Sanchez, a blogger at the libertarian Cato Institute, busted Lott, and The Washington Post broke the story in February 2003. "I probably shouldn't have done it-I know I shouldn't have done it-but it's hard to think of any big advantage I got except to be able to comment fictitiously," Lott told the Post. He later wrote on his Web site, "I had originally used my own name in chat rooms but switched after receiving threatening and obnoxious telephone calls from other Internet posters."

The careers of John Lott and Steven Levitt overlapped at the University of Chicago from 1997 to 1999. Levitt remains a tenured professor of economics there, and the success of Freakonomics has made him a literary and intellectual star. Lott left the U. of C. for Yale in 1999, then in 2001 joined the American Enterprise Institute, a conservative think tank in Washington, D.C. He left the institute ten days before filing his case against Levitt.

Just when and how the Lott-Levitt feud started is not clear-neither man would directly comment on the lawsuit for this article. Levitt's friend Austan Goolsbee, also an economics professor at the U. of C., remembers when Levitt, then a junior fellow at Harvard, visited Chicago in 1994 to present a paper. Lott had just been named a visiting professor. "Even before Steve was on the [academic] job market, John came to the first seminar Steve was giving at Chicago and brought his own slides to the talk and attempted to get up and rebut what Steve was saying during Steve's own workshop," Goolsbee says. "I cannot even tell you how unusual that is-I have never heard of anything like that happening."

Levitt seemed bemused by the confrontation, Goolsbee says, and in fact it might have helped attract him to Chicago. "He thought, Hey, this is a place where people take it so seriously, guys bring their own slides trying to push you out of the way," Goolsbee says. In any case, "it was certainly not a situation where they [Lott and Levitt] were good friends that fell out."

Daniel Polsby, dean of George Mason Law School and a former professor at Northwestern University, has known Lott for 15 years and contributed a jacket blurb for Lott's More Guns, Less Crime. "Levitt is a very unassuming guy, sort of a nebbishy guy, actually, though he does some edgy work," Polsby says. By contrast, Lott is "a man of almost unparalleled personal intensity. There is something of a mad scientist about him. He is one of the most energetic, gifted econometricians of his generation, if not in history. But he seems incapable of distinguishing between large disagreements and small disagreements." He adds, "I don't believe that he has any personal animus" against Levitt.

Although Lott is a fierce advocate of gun rights, one of the ironies of their dispute is that Levitt has not been an advocate of gun control. Indeed, following a family tragedy, he published an article that could well be used to bolster the anti-gun-control side. In 1999, Levitt's first child, Andrew, died suddenly at age one of pneumococcal meningitis. Afterwards, Steve and his wife, Jeannette, joined a support group for parents who had lost children, and Steve was amazed at the number of stories he heard of kids drowning in backyard swimming pools. He wrote an op-ed article published in the July 28, 2001, Chicago Sun-Times demonstrating that children were much more likely to drown in swimming pools than to get shot.

Also that year, Levitt was named to take part in a National Academy of Sciences study of gun issues. In August 2001, a University of Tennessee law professor named Glenn H. Reynolds, the author of the popular, libertarian-leaning blog InstaPundit, and pro-gun activist Dave Kopel wrote an article for National Review Online complaining that the upcoming conference was stacked with anti-gun people. They quoted an anonymous source calling Levitt, in particular, "rabidly anti-gun."

Levitt fired off an e-mail message to Reynolds that same day: "I don't understand your National Review article in which I am described as ‘rabidly anti-gun.' No one who knows me would describe me that way. I love to shoot guns and would own them if my wife would let me. . . . I have never written anything even remotely anti-gun. I think your sources must have me confused with someone else." Reynolds posted Levitt's comments on InstaPundit.

In continuing online debates over gun issues, Reynolds and Kopel have refused to identify the anonymous source. However, Tim Lambert, a computer scientist in Australia who maintains an anti-Lott blog, has said on his blog that Levitt told him he was nearly certain that Lott was the source.

In March 2003 Lott published another book, The Bias Against Guns. In it he wrote, "Steve Levitt, an economist, has been described in media reports as being ‘rabidly anti-gun.'" (If Lott actually was the original source of this quote, he deserves some kind of medal for audacity.) In a footnote, Lott went on to accuse Levitt of writing the swimming pool article merely to hide his true feelings about guns. Lott found it "strange that Levitt would write his first op-ed piece" just when he was about to serve on an aca­demic panel that had been attacked as anti-gun. He added that the staff director of the panel had cited Levitt's op-ed "as evidence that Levitt believed the same things that [Lott] believed on guns. Personally knowing Levitt, I know that was not true and one could point to several of Levitt's academic papers. But the op-ed served its purpose." (Levitt has said he wrote the article nearly a year before it was published.)

As Levitt gained fame, he teamed up with Stephen J. Dubner, a New York journalist, to write Freakonomics: A Rogue Economist Explores the Hidden Side of Everything, which came out from HarperCollins in April 2005. In a chapter titled "Where Have All the Criminals Gone?" Freakonomics devotes one page to John Lott. It mentions the Mary Rosh scandal and adds, "Then there was the troubling allegation that Lott actually invented some of the survey data that support his more guns/less-crime theory. Regardless of whether the data were faked, Lott's admittedly in­triguing hypothesis doesn't seem to be true. When other scholars have tried to replicate his results, they found that right-to-carry laws simply don't bring crime down."

In May 2005, an economist in Texas challenged Levitt's characterization of Lott's research and pointed out that Lott had guest-edited the October 2001 special issue of The Journal of Law and Economics, published by the University of Chicago Press. As a whole, the ten articles in the journal backed Lott's conclusions. According to the lawsuit, Levitt e-mailed back: "It was not a peer refereed edition of the Journal. For $15,000 he was able to buy an issue and put in only work that supported him. My best friend was the editor and was outraged the press let Lott do this."

Eleven months after this exchange, Lott sued Levitt and HarperCollins (but not Dubner) for defamation. Lott seeks unspecified damages and a court order to halt publication of the book until the allegedly defamatory parts are removed and replaced by a retraction. Levitt's lawyers, Slade R. Metcalf of New York and David P. Sanders of Chicago, say in their court response that such an injunction against publication has never happened in a libel case.

Lott's lawsuit hangs on two seemingly simple but academically fraught statements: the research was not replicated and the special issue of the journal was not peer refereed.

Lott contends that "‘replicate' has an objective and factual meaning in scholarship"-it means that other researchers using the same data in the same way will get the same results. Thus, he says, Levitt's use of the term amounts to "alleging that Lott falsified his results." Levitt's lawyers reply that Freakonomics is written in "everyday language" and is aimed at the general reader.

"Peer refereed" (or "peer reviewed") refers to the standard practice at scholarly journals of sending a potential article to several other scholars to vet and approve before the work is published. To uphold academic impartiality, the writer does not know the peers' names. In an e-mail to me, Lott said, "If you were to look at a physical copy of the journal you would see that all of the papers thank anonymous referees for refereeing their papers." (As for whether he was able to "buy an issue," Lott says in the suit that he "raised funds for" publishing the special issue.)

The "best friend" editor whom Levitt mentioned in his e-mail was Austan Goolsbee. "I was the lead editor at the time that special issue was printed, but not when it was prepared," Goolsbee says. The journal collected papers delivered at a conference sponsored by the American Enterprise Institute and the Center for Law, Economics and Public Policy at Yale Law School.

"In one sense," Goolsbee says, symposium papers are peer reviewed "in that the articles sometimes go out" for critiquing. "But Steve Levitt is quite right that the standards are infinitely lower on a conference volume. The acceptance rate for papers at The Journal of Law and Economics is something like 8 to 10 percent. This issue had something like ten papers and like most conference articles, none [I believe] were rejected. That's a one-in-a-billion event that you would get all of those papers in."

At least two contributors, however, told me that their papers were indeed reviewed. Bruce Benson of Florida State University says he made "significant revisions" in the article he coauthored to address criticism from two referees. "I was surprised when I heard that Levitt made this claim because I actually had guessed that he was one of the anonymous reviewers of my paper. . . . Apparently this was not the case."

T. Nicolaus Tideman of Virginia Tech, coauthor of another article in the journal, saw his paper at first rejected by a referee, but he rewrote it and then it was accepted. Tideman said the article analyzed Lott's More Guns, Less Crime data in two different ways and the data held up both times.

Winning a lawsuit for defamation is tough. The Media Law Resource Center, based in New York, keeps score. From 1980 through 2005, "plaintiffs [against media defendants] ultimately won and got to keep the entire trial damage award in only 18.7 percent of the cases that went to trial and verdict," according to a Resource Center report. In 2005, only 14 cases even went to trial.

The courts have generally protected "robust public debate" on policy issues, especially when the debaters are public figures. (Having swum in the whirlpool of gun-control debate for eight years, Lott presumably would be a public figure.) To win a defamation suit, a public figure must prove that the defendant had "actual malice," knowing that his allegations were false or having "reckless disregard" for whether they were true or false.

"The word ‘malice' is misleading," says Frederick Schauer, a professor at Harvard Law School and an expert on the First Amendment. (Schauer stresses that he has no comment on the Lott case.) "What a public figure must prove . . . [is] intentional falsity. And the public figure must prove this with ‘convincing clarity.' . . . All of which is to say that a public figure has a very hard time winning a libel suit."

In June, Levitt and HarperCollins asked Judge Ruben Castillo to dismiss Lott's case. Lott's lawyer, Stephen H. Marcus of Washington, D.C., has objected to the motion and is pressing for a quick trial.

Meanwhile, Freakonomicshas passed its first year on the New York Times best seller list, and Levitt and his coauthor, Dubner, are writing a monthly column on economics for The New York Times Sunday Magazine. Levitt's friend Goolsbee also has started writing a monthly column for the Times.

Lott, who lives in Virginia, says he might have a new job to announce "relatively soon."

And what does this case say about the underlying debate-questions about how social science can guide public policy about gun control? Voters and legislators apparently must rely on their own gut feelings about the Second Amendment. The science base is just too weak so far to settle policy disputes. The National Academy of Sciences study in which the "rabidly anti-gun" Levitt participated said as much. It called for more research, because nobody really knows how gun-control laws affect crime and society.

Well, maybe Mary Rosh knows.