TY  - JOUR
AU  - Sacerdote,Bruce
AU  - Marmaros,David
TI  - How Do Friendships Form?
JF  - National Bureau of Economic Research Working Paper Series
VL  - No. 11530
PY  - 2005
Y2  - August 2005
UR  - http://www.nber.org/papers/w11530
L1  - http://www.nber.org/papers/w11530.pdf
N1  - Author contact info:
Bruce Sacerdote
6106 Rockefeller Hall
Department of Economics
Dartmouth College
Hanover, NH 03755-3514
Tel: 603/646-2121
Fax: 603/646-2122
E-Mail: Bruce.I.Sacerdote@dartmouth.edu

David Marmaros
M2  - featured in NBER digest on 2005-08-01
AB  - We examine how people form social networks among their peers. We use a unique dataset that tells us the volume of email between any two people in the sample. The data are from students and recent graduates of Dartmouth College. First year students interact with peers in their immediate proximity and form long term friendships with a subset of these people. This result is consistent with a model in which the expected value of interacting with an unknown person is low (making traveling solely to meet new people unlikely), while the benefits from interacting with the same person repeatedly are high. Geographic proximity and race are greater determinants of social interaction than are common interests, majors, or family background. Two randomly chosen white students interact three times more often than do a black student and a white student. However, placing the black and white student in the same freshman dorm increases their frequency of interaction by a factor of three. A traditional "linear in group means" model of peer ability is only a reasonable approximation to the ability of actual peers chosen when we form the groups around all key factors including distance, race and cohort.
ER  -