Changes

These results contribute to the growing literature on the industrial impact of academic research. The bulk of this literature has focused either on *On the role of patents and publications in the transfer process (see : Adams 1990, Henderson et al. 1998, and Jaffe et al. 1993) or on *On consulting, sponsored research or institutional ties (see : Cohen et al. 1998; Mansfield 1995; Zucker et al. 1994, 1998). While several recent papers provide evidence on *On the nature of university licensing (e.g., : Jensen and Thursby 2001, Mowery et al. 2001a,b, Mowery et al. 2001, Siegel et al. 1999, Thursby et al. 2001, Thursby and Kemp 2001), none *None of them provides a structure that allows analysis of the sources of growth.