Science magazine officially retracted a major study on same-sex marriage and public opinion on Thursday without the consent of the lead author, UCLA graduate student Michael J. LaCour.
The events leading to the retraction became public on May 19, when the article’s second author, Columbia University political science professor Donald Green, issued a request for the retraction based on evidence that the study data were at least in part falsified.
As The Huffington Post reported last week:
The LaCour-Green study had examined the work of activists with the Los Angeles LGBT Center. After California’s gay marriage ban passed in 2008, activists at the center had more than 12,000 one-on-one conversations in Los Angeles neighborhoods with people who overwhelmingly supported the ban. LaCour’s idea was to see if those conversations produced any lasting change. He purportedly designed a randomized experiment to replicate those conversations, with a series of follow-up surveys online to test how the anti-gay voters felt about gay rights and gay marriage over time. Those who were contacted by the openly gay canvassers showed substantially more positive attitudes toward gay marriage as much as nine months later.
But according to a report issued Tuesday [May 19] by two University of California, Berkeley, graduate students and a Yale professor, there are enough questions about the data to warrant retracting the study. Retraction Watch broke the story Wednesday [May 20] about what students David Broockman (soon to be an assistant professor at Stanford) and Joshua Kalla and Yale professor Peter Aronow found.
After the LaCour-Green study was published, Broockman and Kalla were impressed by its findings and wanted to extend the research. In January 2015, they found some patterns in the data that seemed to be too perfect -- statistically speaking, there was less variance in the results than there should have been. Some social scientists had noticed this when the study was first published.
As Broockman and Kalla continued their work, they wrote in their report, they uncovered more irregularities. When the pair noticed that their own study had a much lower response rate (the proportion of people contacted who actually respond to a survey), they asked the survey firm that allegedly gathered data for LaCour, Qualtrics, how it achieved such a high response rate. They said the firm replied that it had no record of the project.
This is what happened next according to their report and Green's letter to Science: The statistical irregularities continued to mount, and the pair recruited Aronow to help with their analysis. ... Broockman and Kalla contacted Green. Green said that he had joined the study after the data had been collected and thought that the irregularities Broockman and Kalla had uncovered were, indeed, highly suspicious. Green reached out to LaCour’s adviser at UCLA, professor Lynn Vavreck, and the two of them decided that Vavreck would confront LaCour and ask him to provide his data. Initially, LaCour claimed he had accidentally deleted the file with the necessary information, but again Qualtrics said it could not verify that the data had been deleted or that the study took place. It seemed increasingly clear to Green that no follow-up surveys had ever been conducted and that LaCour may have taken data from existing studies and manipulated the numbers to achieve the results he wanted.
Thursday's statement from Science Editor-in-Chief Marcia McNutt cites two reasons for retracting the study. First, claims that survey respondents had been given cash payments to participate and refer family and friends to participate in the survey were inaccurate. Second, the funding statement was false. LaCour had misrepresented that funding for the study came from the Williams Institute, the Ford Foundation, and the Evelyn and Walter Haas Jr. Fund.
McNutt's statement notes that both of these falsifications have been confirmed by LaCour’s attorney, although it also points out that LaCour does not agree with the retraction.
LaCour did not immediately respond to requests for comment from The Huffington Post, but he has told Science Insider that he will provide a full report in his defense as quickly as possible. His website has a statement that he will respond on or before May 29.
For Jim Key, chief marketing officer for the Los Angeles LGBT Center, which partnered with LaCour and Green on the study, the only upside of the retraction is that researchers will now go out and actually quantify whether the center's methods are successful.
“We support the retraction and are very happy to be working with other researchers, David Broockman and Josh Kalla, to get accurate data regarding our voter persuasion work," Key told HuffPost.