EconLit -The primary economics database, covers more than 550 international economic journals. EconLit source material includes journal articles, essays, research papers, books, dissertations, book reviews, and working papers.
NBER Working Papers -Includes working papers (1973- ) (NBER Working Papers have not undergone the review accorded official NBER publications), NBER corporate history documents (1921-present), and NBER books (1921- )
Economics Research Network (via the Social Sciences Research Network) Economics research papers, public policy research papers, economics departments papers, and government & public agency research papers. Requires free registration
CIAO: Columbia International Affairs Online Includes working papers from private institutions (e.g., Brookings Institution, American Enterprise Institute, Cato Institute), university research institutes, occasional papers series from NGOs, foundation-funded research projects, and proceedings from conferences.