Knowledge production function approaches to estimation of knowledge flows in regions have recently come under attack not to open the ’black box’ of knowledge creation and it has been questioned whether spillovers really are the key determinant of knowledge diffusion rather than market...

Industrial classifications offer arguably poor schemes for classifying innovative activity. Moreover, a single measure incorporating technological relatedness between the inherent classes, captures the neglected issue of Jacobs (1969) and Marshall (1920), that the degree of relatedness of...