When Lott cited the statistic peripherally on page 3 of his book, he attributed it to "national surveys." In the second edition, he changed the citation to "a national survey that I conducted." He has also incorrectly attributed the figure to newspaper polls and Florida State University criminologist Gary Kleck.
Last fall, Northwestern University law professor James Lindgren volunteered to investigate the claimed existence of Lott's 1997 telephone survey of 2,424 people. "I thought it would be exceedingly simple to establish" that the research had been done, Lindgren wrote in his report (posted online here.).
It was not simple. Lott claims to have lost all of his data due to a computer crash. He financed the survey himself and kept no financial records. He has forgotten the names of the students who allegedly helped with the survey and who supposedly dialed thousands of survey respondents long-distance from their own dorm rooms using survey software Lott can't identify or produce.
Assuming the survey data was lost in a computer crash, it is still remarkable that Lott could not produce a single, contemporaneous scrap of paper proving the survey's existence, such as the research protocol or survey instrument. After Lindgren's report was published, a Minnesota gun rights activist named David Gross came forward, claiming he was surveyed in 1997. Some have said that Gross's account proves that the survey was done. I think skepticism is warranted.