Industrial districts, technological innovation and I-district effect: A question of volume or value?

The I-district effect establishes the existence of dynamic efficiency in Marshallian industrial districts in the form of a positive innovative differential comparing to the average of the economy. The hypothesis has been empirically validated for the case of technological innovation using patent indicators. Empirical research has assumed that all types of patentable figures (models of innovation, national patents, EPO, WIPO) have the same weight regardless of its actual or expected market value, which may be questionable given the differences in coverage, protection and cost of each figure. In this article we question the existence of the I-district effect when each patent is weighted by its expected potential value. As the I-district effect theory predicts, the relative differential effect is maintained even in the presence of the weighting, rejecting that the industrial district specializes only in low quality patents. However, in this case, the primacy of industrial district as the most innovative local production system can be outpaced by other local production systems.