I spent a heck of a long time trying to get differences between adotpion driven
by cohesion vs structural equivalence and generally found that in the empirical
data available the two are highly correlated For example, in one unpublished
analysis using weibull regression on the time to adoption for Brazilian farmers
adption influences by structurally equivalent alters had an odds ratio of 2.85
(p<.01) whereas it was 1.63 (p<.05) for cohesive alters. This same analysis
returned non-significant effects for the Korean family planning and medical
innovation data for either SE or cohesion. You might expect structural
equivalence to drive diffusion for the Brazilian farmers because hybrid seed
adoption, in large part, is a business decision. In the end, as many of you
know, I concluded that thresholds vary and this what drives adoption decisions.
In pure contagion, uniformly low thresholds, you might find differences between
SE and cohesion, and local areas of SE rather than cohesion (or vice versa) but
I think it is going to be very hard to find. This will be particularly true for
later adopters who have networks filled with adopters. Theoretically it's out
there, but we've yet to collect data that show it (in my opinion).
One possibility is to look at whether people adopt because their network ties
share information with them or whether they feel pressure to conform. In which
case you could isolate those who are late adopters but adopted without having
network exposure, but then score high on a "desire to conform" scale. In a
sense the question brings to mind social influence at 2 levels, the immediate
level where people get information from their peers, and the macro level where
people sense what the community norms are going to be and they monitor the
situation to see when the winds shift to favor adoption. - Tom V.
David Lazer wrote:
> Below is a question a colleague of mine, Steve Kelman, presented to me, and
> I did not really have any insights, so I am forwarding it on to you:
> Do people know of any empirical tests comparing information cascade
> explanations versus social comparison/conformity explanations for the
> behavior of late adopters?
> Any leads would be appreciated.
> David Lazer
> Asst. Professor of Public Policy
> Kennedy School of Government
> Harvard University
> Cambridge, MA 02138
> [log in to unmask]
Thomas W. Valente, PhD
Director, Master of Public Health Program
Department of Preventive Medicine
School of Medicine
University of Southern California
1000 Fremont Ave.
Building A Room 5133
Alhambra CA 91803
phone: (626) 457-6678
fax: (626) 457-6699
email: [log in to unmask]