This document summarizes findings from a large-scale OECD study on the role of firms in wage inequality. The key findings are: 1) Firm pay practices account for about one-third of overall wage inequality between workers. 2) There are widening productivity gaps between firms, with the most productive firms pulling away, contributing to rising wage dispersion. 3) Barriers to job mobility between firms further widens wage gaps between similar workers at different firms. The study provides evidence that both skills policies and policies targeting lagging firms and barriers to mobility are needed to strengthen inclusive productivity growth and reduce wage inequality.