This book uniquely enriches and empowers its readers. It enriches them by giving them the most detailed and extensive data available on the policies and preferences of key democratic actors—parties, governments, and electors in 25 democracies over the post-war period. Estimates are provided for every election and most coalitions of the post-war period and derive from the programmes, manifestos, and platforms of parties and governments themselves. Thus, they form a uniquely authoritative source, recognized as such and provided through the labour of a team of international scholars over 25 years. The book empowers readers by providing these estimates on the website http://manifestoproject.wzb.eu/MPP1. The printed text provides documentation and suggested uses for data, along with much other background information. The changing ideologies and concerns of parties trace general social developments over the post-war period, as well as directly affecting economic policy making. Indispensable for any serious discussion of democratic politics, the book provides necessary information for political scientists, policy analysts, comparativists, sociologists, and economists. A must for every social science library—private as well as academic or public.