There is clear evidence that economic activity, and especially industrial activity, is unequally located across the Spanish geography. Against this background, this paper presents a model to analyse the influence of external economies on the territorial distribution of the employment of different industrial sectors. Following an extension of Marshalls approach, the proposed model introduces explanatory variables that quantify different types of external economies. Some of these are traditional in this type of analysis and measure urbanisation and location economies. However, others have not been reflected in previous analysis due to the difficulty of measuring them. These variables measure links between sectors determined by the presence of providers and technological spillovers which can also influence the location of manufacturing activities. A new element in the analysis of the Spanish case is that we use a database which gathers information at the local level. The results that emerge from the econometric estimation show that external economies influence the geographical distribution of industrial activities. Nevertheless, this impact is very different depending on the industrial sector analysed.

Key words: industrial location, external economies, technological spillovers, spatial econometrics.
JEL classification: R3, L60, C53.