From the Washington Post:

Jason Richwine, the co-author of a controversial immigration study
released this week by the Heritage Foundation, tells Post Politics that
he has resigned his position with the organization.

"Yes, that's right," Richwine wrote in a brief e-mail. Heritage confirmed that he resigned.

The study written by Richwine and Robert Rector argued that the immigration reform bill would cost $6.3 trillion,
but it was widely panned by conservative groups pushing for immigration
reform as not accounting for the economic benefits of immigrants.

Complicating matters were a series of revelations about Richwine,
including that he had written a doctoral thesis at Harvard University
arguing that the United States should focus its immigration efforts on those with high IQs and that he had written for a Web site that describes itself as "nationalist."