Jason Richwine, the Harvard Ph.D. graduate who co-authored the Heritage Foundation’s controversial report on the costs of amnesty, resigned his position at the venerable conservative think tank Friday.

“It is our long-standing policy not to discuss internal personnel matters,” Heritage Foundation Vice President of Communications Michael Gonzalez tells The Washington Examiner.

Richwine first joined the Heritage Foundation in 2010 after earning his doctorate in public policy in 2009 from Harvard University while on an American Enterprise Institute dissertation fellowship.

Richwine’s Harvard dissertation asserted that, “No one knows whether Hispanics will ever reach IQ parity with whites, but the prediction that new Hispanic immigrants will have low-IQ children and grandchildren is difficult to argue against.”

Earlier this week, Gonzalez emphatically disavowed Richwine’s dissertation. “The Harvard paper is not a work product of The Heritage Foundation. Its findings do not reflect the positions of The Heritage Foundation or the conclusions of our study on the cost of amnesty to U.S. taxpayers, as race and ethnicity are not part of Heritage immigration policy recommendations,” Gonzalez said.