Links down this column of the page refer to various data sites that have proved useful over the years. I invite nominations for new sites and information about inactive sites.
Washington Post, gateway to government Internet resources
FEDSTATS (Index to federal agency statistics on line)
Statistics of Income Division (Internal Revenue Service)
Inter-university Consortium for Political and Social Research (ICPSR), the world's largest archive of computer-readable social science data
National Election Study (NES), for information about public opinion studies