TY  - JOUR
AU  - Brock,William A.
AU  - Durlauf,Steven N.
TI  - Adoption Curves and Social Interactions
JF  - National Bureau of Economic Research Working Paper Series
VL  - No. 15065
PY  - 2009
Y2  - June 2009
UR  - http://www.nber.org/papers/w15065
L1  - http://www.nber.org/papers/w15065.pdf
N1  - Author contact info:
William Brock
Department of Economics
University of Wisconsin
1180 Observatory Drive
Madison, WI   537061393
E-Mail: wbrock@ssc.wisc.edu

Steven N. Durlauf
Department of Economics
University of Wisconsin
1180 Observatory Drive
Madison, WI  53706-1393
Tel: 608/263-3859
Fax: 608/262-2033
E-Mail: sdurlauf@ssc.wisc.edu
AB  - This paper considers the observational implications of social influences on adoption decisions for an environment of perfect foresight adopters.  We argue that social influences can produce two observable effects: 1) discontinuities in unconditional adoption curves and 2) pattern reversals in conditional adoption curves, in which earlier adoption is found for one group of actors versus another when "fundamentals" suggest the reverse ordering should occur; in turn the presence of either of these features can, under weak assumptions, be interpreted as evidence of social influences.  As such, these properties are robust implications of social effects.
ER  -