After the IPCC released its February 2007 report, the American Enterprise Institute offered British, American and other scientists $10,000 plus travel expenses to publish articles critical of the assessment. The institute had received more than US$1.6 million from Exxon, and its vice-chairman of trustees was former head of Exxon Lee Raymond. Raymond sent letters that alleged the IPCC report was not "supported by the analytical work." More than 20 AEI employees worked as consultants to the George W. Bush administration. Despite her initial conviction that climate change denial would abate with time, Senator Barbara Boxer said that when she learned of the AEI's offer, she "realized there was a movement behind this that just wasn't giving up."