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Study had claimed that a brief discussion with a gay canvasser could make a voter more likely to support gay marriage.

Study had claimed that a brief discussion with a gay canvasser could make a voter more likely to support gay marriage.

Fibonacci Blue/Flickr (CC BY 2.0)

Gay marriage study author LaCour issues defense, but critics aren't budging

The lead author of a now-retracted study of voter persuasion and gay marriage published by Science has released a lengthy response to some of the allegations that led to the retraction.

In the 23-page document, political science graduate student Michael LaCour of the University of California (UC), Los Angeles, attacks the methods and motives of researchers who raised questions about his research, but confirms that he lied about some funding sources and the incentives used to attract participants. And he admits that he destroyed the data used to produce the study, claiming that action was required by a UC Los Angeles institutional review board (IRB) in order to protect the privacy of participants.

LaCour’s response does not, however, directly answer a number of other questions surrounding the study—and it raises new issues. LaCour does not address, for example, why the company that he claimed had conducted his surveys says it has no knowledge of the researcher or his project and does not have the capability to conduct some of the claimed work. (After the statement’s release, LaCour told The New York Times that he did not use that company, but another unidentified company.)

The statement also suggests that LaCour did not originally have IRB approval for his project, (Subsequently, UC Los Angeles officials contaced ScienceInsider to say he never obtained approval.) It is not clear if LaCour notified Science of that issue. Other social scientists also say that, had LaCour obtained IRB approval, it would be unusual for an IRB to require a researcher to destroy all of their raw data, but such approvals often do require researchers to “de-identify” data, or strip it of any identifying features, such as names, addresses, or phone numbers.

"I take full responsibility for errors in the design, implementation, and data collection regarding the field experiments and panel survey reported in LaCour and Green (2014). I also take full responsibility and apologize for misrepresenting survey incentives and funding,” LaCour wrote.

But LaCour faults the three researchers who publicly challenged his work—David Broockman and Joshua Kalla of UC Berkeley and Yale University researcher Peter Aronow—for alleged flaws in their own statistical analyses of his work and for bringing their concerns to Green, rather than confronting him directly. The trio’s “decision to not present the lead author with the critique directly, by-pass the peer-review process, privately investigate data collection activities without knowledge or consent of the author, demand confidential identifying information from respondents in a study without grounds or standing to do so, publicize unsubstantiated allegations and hearsay prior to a formal investigation, is unprecedented, unethical, and anomalous in the relevant literature,” LaCour wrote.

Broockman, Kalla, and Aronow are standing by their critique. “In our view, none of the claims made in LaCour’s reponse meaningfully address the concerns articulated in our report, Professor Green’s retraction request, or the Science retraction,” they wrote in a statement posted on Kalla’s Twitter account on 29 May.

In a 28 May statement, Science Editor-in-Chief Marcia McNutt said the journal was retracting the paper, at Green’s request, because LaCour had made false statements about his funding sources and incentive methods and could not produce the raw data that would allow others to reproduce the results. LaCour did not agree to the retraction.

Officials at UC Los Angeles have said they are conducting an investigation of the research.

*Correction, 1 June, 2:02 p.m.: This story incorrectly reported that LaCour's statement suggested that he ultimately received IRB approval for his study shortly before publication. UC Los Angeles officials say he never received IRB approval.