Angus Maddison On-line
http://www.ggdc.net/Maddison/
Angus Maddison an economics professor whose recent books - Monitoring the World Economy and The World Economy: A Millennial Perspective - are major works in the field of economic history. Dr. Maddison's site contains links both to excerpts from his books and to much of the data within them. (His books are also available via OECD iLibrary.)
Comparative Welfare States Data Set (CWSDS)
http://www.lisproject.org/publications/welfaredata/welfareaccess.htm
The CWSDS is a joint effort by comparative welfare-state scholars such as Evelyne Huber, Charles Ragin, John D. Stephens, and Duane Swank. The data cover 18 OECD countries from 1960 onwards and include many economic, political, and policy variables.
Eurostat
http://epp.eurostat.ec.europa.eu/
Eurostat is the statistical office of the European Union. Eurostat collects statistical information from the member states of the EU. Much of their data are accessible on-line here. The EDC also has a DVD database with more extensive time-series coverage (see below).
Groningen Growth and Development Centre (GGDC)
http://www.ggdc.net/
The GGDC is run by the University of Groningen in the Netherlands. It offers a variety of downloadable datasets with economic data for both developed and developing countries (although the most detailed data are for developed countries). The data focus on various measures of economic output and productivity, at both national and sectoral level. Users can access the data here.
International Labour Organization
http://www.ilo.org
The ILO is the main international labor-rights advocacy group in the world and has brought together a variety of information about labor rights and working conditions internationally. You can access their databases directly at http://www.ilo.org/global/statistics-and-databases/lang--en/index.htm. The LABORSTA database and the Key Indicators of the Labour Market are particularly useful as sources for labour market data.
International Monetary Fund (IMF) International Financial Statistics
http://elibrary-data.imf.org/
The International Financial Statistics, which is part of the IMF's eLibrary of databases, is a standard source for macroeconomic data, with a focus on monetary and financial topics, both international and domestic. This resource is also available via Databases at Emory and via CD-ROM in the Data Center.
OECD iLibrary (Organization for Economic Cooperation and Development)
http://www.oecd-ilibrary.org/
The OECD iLibrary is an online interface that provides full-text access to OECD studies, periodicals, and dozens of statistical databases. The topical range of the iLibrary is considerable and covers areas such as agricultural policies, environmental indicators, social expenditures, labour markets, national accounts, foreign trade and FDI, and various industry-level data. While its focus is on wealthier developed countries, the iLibrary also includes OECD reports and publications on selected non-member countries such as the BRIC countries of Brazil, Russia, India, and China. This resource is also available via Databases at Emory.
Penn World Tables
The Penn World Tables is a source for internationally-comparable macroeconomic data on economic output for the period 1950-2009. The most recent version of the PWT is available at http://pwt.econ.upenn.edu/. An older version with coverage from 1950-1992 (and some variables not yet available in the newest version) can be found at http://datacentre.chass.utoronto.ca/pwt/.
World Development Indicators (World Bank)
http://data.worldbank.org/data-catalog/world-development-indicators
The World Development Indicators provide convenient access to hundreds indicators on over 200 countries and territories. Data are available annually from 1960 forward, with variation across countries and indicators. The database is part of the Bank's Data Catalog of statistical databases and other data collections. The WDI is also accessible via Databases at Emory and on CD-ROM in the Data Center.