%T Variety and Irreversibility in Scientific and Technological Systems: the Evolution of an Industry Network %P 216-239 %I Routledge %V 2 %E Antonio Nicita %E Ugo Pagano %D 2001 %L eprints656 %S Routledge Siena studies in political economy %A Fabio Pammolli %A Luigi Orsenigo %A Massimo Riccaboni %C London %B Antonio Nicita and Ugo Pagano (eds). The Evolution of Economic Diversity