TY  - JOUR
AU  - Trajtenberg,Manuel
AU  - Yitzhaki,Shlomo
TI  - The Diffusion of Innovations: A Methodological Reappraisal
JF  - National Bureau of Economic Research Working Paper Series
VL  - No. 1008
PY  - 1982
Y2  - October 1982
UR  - http://www.nber.org/papers/w1008
L1  - http://www.nber.org/papers/w1008.pdf
N1  - Author contact info:
Manuel Trajtenberg
Eitan Berglas School of Economics
Tel-Aviv University
Tel-Aviv 69978
ISRAEL
Tel: 972-3-640-9911
Fax: 972-3-640-9908
E-Mail: manuel@post.tau.ac.il

Shlomo Yitzhaki
Department of Economics
Hebrew University
Mount Scopus
Jerusalem 91905
ISRAEL
Tel: 972-2-659-2201
Fax: 972-2-652-2319
E-Mail: shlomo.yitzhaki@huji.ac.il
AB  - Studies of diffusion have traditionally relied on specific distributions-primarily the logistic- to characterize and estimate those processes.We argue here that such approach gives rise to serious problems of comparability and interpretation, and may result in large biases inthe estimates of the parameters of interest. We propose instead the Gini's expected mean differenceas ameasure of diffusion speed, discuss its advantages over the traditional approach, and tackle with it the problems of truncated processes, inter-group comparisons, and related issues. We also elaborateon the use of the hazardrate, and suggest some possible extensions. The diffusion of CT scanners is presented as an illustration.
ER  -