Transport Infrastructure,Agglomeration Economies,and Firm Birth: Empirical Evidence from Portugal*

Abstract. This paper uses municipality‐level data to study firm birth in Portugal from 1986 to 1997. This is a period of significant improvements to the Portuguese motorway network raising important questions as to its impact on the spatial pattern of firm birth. The paper focuses on the effect of such large‐scale road investment together with the role played by agglomeration economies for firm birth in 13 industry sectors and 9 service sectors. Motorways increase the attractiveness of locations close to the new infrastructure for most sectors. However, marked differences among sectors exist in the way transport improvements affect geographical firm‐birth concentration. The results also indicate that a more diversified local economic environment encourages firm birth, but little evidence is found for agglomeration benefits stemming from sectoral specialization at the local level.