Sachs's economic philosophies have been the subject of both praise and criticism. One of Sachs's strongest critics is William Easterly, a professor of economics at New York University. Easterly reproached "The End of Poverty" in his review for "The Washington Post" and Easterly's 2006 book "White Man's Burden" is a response to Sachs's argument that poor countries are stuck in a "poverty trap" from which there is no escape except by massively scaled-up foreign aid. Sachs himself has emphasized the need for a multifaceted approach to economic development, of which increased and responsible foreign aid is nearly always a necessary part. Easterly presents statistical evidence that he claims proves that many emerging markets attained their higher status without the large amounts of foreign aid Sachs proposes.