The Penn World Table provides purchasing power parity and national income accounts converted to international prices for 189 countries for some or all of the years 1950-2007.

Website: www.datacentre.chass.utoronto.ca/pwt/index.html

The National Science Foundation is an independent U.S. government agency responsible for promoting science and engineering through programs that invest over $3.3 billion per year in almost 20,000 research and education projects in science and engineering.

Website: www.nsf.gov

More than 70 agencies in the United States Federal Government produce statistics of interest to the public. The Federal Inter-agency Council on Statistical Policy maintains this site to provide easy access to the full range of statistics and information produced by these agencies for public use.

Website: www.fedstats.gov

Economy.com’s FreeLunch provides with free access to over 1,000,000 economic and financial data series.

Website: www.economy.com