Firms are more productive on average in larger cities. Two main explanations have been offered: firm selection (larger cities toughen competition, allowing only the most productive to survive) and agglomeration economies (larger cities promote interactions that increase productivity), possibly...

We examine how agglomeration economies have influenced labour earnings in France over forty years. First, we define 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...