During the post-war period, income inequality fell dramatically in the Western world, a phenomenon that has come to be called The Great Compression (Goldin and Margo, 1992). Sweden particularly stands out as a country that went from very high levels of income inequality to becoming known as the world's most equal country (Bengtsson, 2020; Piketty, 2014). In this project, we study the role of companies in this development, a perspective that is missing in the debate about what led to the Great Compression. Within the project, we are creating a unique longitudinal micro-database with information about income, workplace, and residential address at the individual level for Stockholm's entire population every year between 1940 and 1970. With this database, we will study how the income distribution developed for employees within and between all of Stockholm's companies and what drove this development.