Weexamine how agglomeration economies have inuenced labour earnings in France over forty years. First, we de ne cities dynamically to account for their changing footprints. Our findings show that aggregate wage growth is mainly driven by growth in larger cities, rather than smaller ones or by population shifts across cities. We estimate individual wages incorporating time-varying city and individual xed e ects, and analyse how city characteristics (employment density, area, and market access) and their returns impact wage evolution. Changes in the values of these characteristics have minimal e ect, but changes in their returns signi cantly inuence wages, with notable variation across cities. Overall, aggregate wage growth in France re ects larger returns to larger city size. Our model, that incorporate the impact of agglomeration economies on city size and population, suggests that changes in returns do not drive population or area changes su ciently to impact aggregate labour earnings, supporting our empirical ndings.