Pré-publication, Document de travail: The purpose of this study is to construct and then analyze a new dataset that systematically documents the labor share of national income for more than 200 countries over the past 70 years. Using new archival data on national accounts, we measure the long-run evolution of national income between factor shares (labor and capital). In addition to its implicit impor- tance in the study of inequality, the data naturally lends itself to novel empirical analysis of international patterns in tax progressivity, trade integration, technology, and labor force com- position.