Introduction

The purpose of this chapter is to provide some aggregate evidence on the differences among sectors in terms of innovative activities and trends of relevant economic variables, such as value added, employment and labor productivity. It draws an aggregate picture in terms of stylized facts and open issues, with a specific focus on the sectors that are the subject of the different case studies of this book. It complements the conceptual discussion in chapter 1 and assesses the way sectoral differences have fostered structural changes in the last twenty years in industrialized countries. It points out the different innovative and economic performances of industrialized countries in each sector. Finally, it discusses the way the literature on systems of innovation can tackle these processes of sectoral transformation and provide analytical insights.

The point of departure is that – in the long run – the main source of growth is related to the ability to create, diffuse and adopt new ideas and apply them to economic activities, and that knowledge and technologies develop unevenly across both sectors and countries (Dosi, Pavitt and Soete, 1990; Nelson, 1991; Nelson and Wright, 1992; Fagerberg, Guerrieri and Versagen, 1999; and Mowery and Nelson, 1999). In particular, creation, adoption and diffusion occur at different rates across sectors, and in different periods of economic history we observe different waves of technical change characterized by specific technological traits.