Notes to the Economic Outlook Annex Tables (OECD)

http://www.oecd.org/economy/outlook/notestotheeconomicoutlookannextables.htm

Active population

Economically active population comprises all persons of either sex who furnish the supply of labour for the production of economic goods and services as defined by the United Nations System of National Accounts during a specified time-reference period.

http://stats.oecd.org/glossary/detail.asp?ID=730


Labor force = Employment + Unemployment

Participation rates  = Labor force / Working-age population (15-64)

http://www.oecd.org/economy/outlook/eosources-notestostatisticalannextables11-19wagescostsunemploymentandinflation.htm#t_13