Persistence of innovation and knowledge structure: Evidence from a sample of Italian firms

The paper investigates the patterns of persistence of knowledge and innovation across a sample of Italian firms in the period 1998-2006. While most of the empirical analysis of persistence focus on innovation as proxied by capital stock or the introduction of process/product innovation, this paper proposes to investigate the persistence of knowledge structure. The analysis draws upon a theoretical representation of knowledge as a collective good, stemming from the recombination of knowledge bits that are fragmented and dispersed across economic agents. In this perspective, knowledge is a co-relational structure, whereby the constituting elements are connected in a dense network of interlinks. On this basis, we derived some important properties of knowledge structure, i.e. the coherence, the cognitive distance and the variety, and investigated their pattern of persistence over time. The empirical analysis is implemented by exploring the autocorrelation structure of such properties within a quantile regression framework, and compare them with the more familiar evidence about knowledge stock. The results suggest that the properties of knowledge are featured by somewhat different patterns with respect to knowledge stock, and that such evidence is also heterogeneous across firms in different quantiles..