ms^m HD2R .M414 WORKING PAPER ALFRED P. SLOAN SCHOOL OF MANAGEMENT Technological Progress and the duration of contribution spans Michael A. Rappa Ko«nraacl Debackere Raghu Garud Massachusetts Institute of Rijksuniversiteit Gent New York University Technology December 1991 SloanWP # 3393-92 MASSACHUSETTS INSTITUTE OF TECHNOLOGY 50 MEMORIAL DRIVE CAMBRIDGE. MASSACHUSETTS 02139 Massachusetts Institute ofTechnology Technological Progress and the duration of contribution spans Michael A. Rappa Koenraad Debackere Raghu Garud Massachusftts Institute of Rijksuntversiteit Gfnt New York University Technology WP December 1991 Sloan # 3393-92 Forthcoming in TechnologicalForecastingandSocialChange, Vol. 42, No. 4 (199*) 1991 MASSACHUSETTS INSTITUTE OF TECHNOLOGY Alfred P. Sloan School of Management Massachusetts Institute ofTechnology 50 Memorial Drive, E52-538 MA Cambridge, 02139-4307 ;M 9 1992