Amid a tidal wave of criticism, Science is retracting a study of how canvassers can sway people's opinions about gay marriage published just 5 months ago. The retraction comes without the agreement of the paper’s lead author, Michael J. LaCour, a political science Ph.D. student at the University of California (UC), Los Angeles. LaCour’s attorney has told Science that LaCour made false claims about some aspects of the study, according to the retraction statement, including misrepresenting his funding sources and the incentives that he offered to survey participants.

“In addition to these known problems, independent researchers have noted certain statistical irregularities in the responses,” Science Editor-in-Chief Marcia McNutt wrote in the retraction statement. “LaCour has not produced the original survey data from which someone else could independently confirm the validity of the reported findings."

McNutt wrote: “The reasons for retracting the paper are as follows: (i) Survey incentives were misrepresented. To encourage participation in the survey, respondents were claimed to have been given cash payments to enroll, to refer family and friends, and to complete multiple surveys. In correspondence received from Michael J. LaCour’s attorney, he confirmed that no such payments were made. (ii) The statement on sponsorship was false. In the Report, LaCour acknowledged funding from the Williams Institute, the Ford Foundation, and the Evelyn and Walter Haas Jr. Fund. Per correspondence from LaCour’s attorney, this statement was not true.”

The retraction comes after Retraction Watch broke the story on 20 May. The storm began brewing weeks earlier when David Broockman and Joshua Kalla, graduate students at UC Berkeley, together with Yale University researcher Peter Aronow, were unable to replicate some aspects of the Science study. It claimed to show that a relatively brief conversation with a canvasser who identified themselves as gay and as an advocate for gay marriage could persuade voters in California to become more supportive of gay marriage. The goal was to test whether persuasion methods used by advocacy groups to sway voters actually worked.

The sleuthing by Broockman, Kall, and Aronow led them to call the survey company that, according to the paper, was used to poll some 9500 people in California. The company revealed that they had done no such survey. The researchers also contacted LaCour's only co-author, Donald Green of Columbia University, who asked for the retraction after LaCour failed to produce data and other materials Green requested.

In recent days, more allegations against LaCour have emerged. One political scientist questions the honesty of some of LaCour's previously published research. There are even questions about a teaching award that LaCour seems to have included on his resume, but then removed. Others have questioned whether Green should have taken authorship on the paper without reviewing the survey data, and whether Science adequately vetted the manuscript.

Meanwhile, LaCour's Ph.D. adviser at UC Los Angeles, Lynn Vavreck, has remained quiet. "The university has asked me not to speak media until the investigation into the research allegations has concluded," she told ScienceInsider by e-mail.

In an e-mail exchange yesterday with ScienceInsider, LaCour promised to provide a full "report" in his defense. LaCour said he is "doing [his] best to finish as quickly as possible."