Measuring social influence is notoriously difficult in observational data. If I like Tin Hat Trio and so do my friends is it because I influenced them or we just have similar tastes, as friends often do. A controlled experiment is called for. It’s hard to figure out how to do that. How can an experimenter cause a subject to like something new and then study the effect on his friends?
Online social networks open up new possibilities. And here is the first experiment I came across that uses Facebook to study social influence, by Johan Egebark and Mathias Ekstrom. If one of your friends “likes” an item on Facebook, will it make you like it too?
Making use of five Swedish users’ actual accounts, we create 44 updates in total during a seven month period.1 For every new update, we randomly assign our user’s friends into either a treatment or a control group; hence, while both groups are exposed to identical status updates, treated individuals see the update after someone (controlled by us) has Liked it whereas individuals in the control group see it without anyone doing so. We separate between three different treatment conditions: (i) one unknown user Likes the update, (ii) three unknown users Like the update and (iii) one peer Likes the update. Our motivation for altering treatments is that it enables us to study whether the number of previous opinions as well as social proximity matters.2 The result from this exercise is striking: whereas the first treatment condition left subjects unaffected, both the second and the third more than doubled the probability of Liking an update, and these effects are statistically significant.
4 comments
Comments feed for this article
November 3, 2011 at 1:33 pm
Heski
I heard a year or two ago (at a strategy conference at Columbia) Duncan Watts who’s now at Yahoo! talk about some related experiments where if I remember correctly he creates groups randomly (online) where he allows you to see what songs others are listening to etc and sees what everyone ends up liking – without social influence you should see tastes random across group and no systematic differences … that’s not what he sees (if I remember right).
I had trouble tracking it down on his webpage (http://research.yahoo.com/Duncan_Watts) but I’m pretty sure it’s covered in his book “Everything is Obvious (Once You Know the Answer): How Common Sense Fails Us” Of course, it could also (easily) be that I’m totally mis-remembering: I’m starting to feel like I may have been to too many disparate conferences …
November 3, 2011 at 3:08 pm
Zizi
But this result could have implication regarding the decision to signal one’s preference, rather than revealing one’s actual preference.
That is, it could be that, if an item attracts attention, or even my peer’s attention, I would be more inclined to signal my similar preference.
I wonder if the study precludes this possibility?
November 4, 2011 at 7:25 am
Anonymous
The work that Heski referred to is Salganik, Dodds & Watts (2006) “Experimental Study of Inequality and Unpredictability in an Artificial Cultural Market”, Science.
November 10, 2011 at 9:33 pm
Lyle_S
I like Tin Hat Trio, especially their version of ‘Willow Weep for Me’ where Willie Nelson sings.