Eur. Phys. J. B 47, 459-466 (2005)
https://doi.org/10.1140/epjb/e2005-00332-y

Innovation flow through social networks: productivity distribution in France and Italy

¹ Department of Applied Mathematics, Research School of Physical Sciences and Engineering, The Australian National University, Canberra ACT 0200, Australia
² Department of Economics, Università Politecnica delle Marche, Piaz.le Martelli 8, 60121 Ancona, Italy

Corresponding author: ^a tiziana.dimatteo@anu.edu.au

Received: 24 November 2004
Revised: 10 July 2005
Published online: 28 October 2005

Abstract

From a detailed empirical analysis of the productivity of non financial firms across several countries and years we show that productivity follows a non-Gaussian distribution with `fat tails' in the large productivity region which are well mimicked by power law behaviors. We discuss how these empirical findings can be linked to a mechanism of exchanges in a social network where firms improve their productivity by direct innovation and/or by imitation of other firm's technological and organizational solutions. The type of network-connectivity determines how fast and how efficiently information can diffuse and how quickly innovation will permeate or behaviors will be imitated. From a model for innovation flow through a complex network we show that the expectation values of the productivity of each firm are proportional to its connectivity in the network of links between firms. The comparison with the empirical distributions in France and Italy reveals that in this model, such a network must be of a scale-free type with a power-law degree distribution in the large connectivity range.