Miren Lafourcade participated to the 13th Meeting of the Urban Economics Association that took place in Columbia University, New York City, on October 12-13. She presented a paper entitled “Labour productivity gains from the “Grand Paris Express” rail project” which is a collaboration with Pierre-Philippe Combes (University of Lyon and Sciences Po) and Laurent Gobillon (Paris School of Economics, CNRS). This paper provides an estimation of the changes in workers’ earnings and firms’ value-added arising from the “Grand Paris Express” metro project. This large transport investment (€29 Bn) is expected to create around 115,000 jobs adding to the natural growth of the Paris region over 2016-2030, and to generate long-run time savings between Parisian suburban areas. The paper quantifies the static and dynamic agglomeration economies conveyed by these job creations, under different migration responses to the project and under different skill endowments of movers.