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How Do Friendships Form?

Listed author(s):
  • David Marmaros
  • Bruce Sacerdote

We examine how people form social networks among their peers. We use a unique data set 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.

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File URL: http://hdl.handle.net/10.1093/qje/121.1.79
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Article provided by Oxford University Press in its journal The Quarterly Journal of Economics.

Volume (Year): 121 (2006)
Issue (Month): 1 ()
Pages: 79-119

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Handle: RePEc:oup:qjecon:v:121:y:2006:i:1:p:79-119.
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  1. Eric A. Hanushek & John F. Kain & Jacob M. Markman & Steven G. Rivkin, 2001. "Does Peer Ability Affect Student Achievement?," NBER Working Papers 8502, National Bureau of Economic Research, Inc.
  2. Falk Armin & Kosfeld Michael, 2012. "It's all about Connections: Evidence on Network Formation," Review of Network Economics, De Gruyter, vol. 11(3), pages 1-36, September.
  3. repec:hrv:faseco:4553034 is not listed on IDEAS
  4. Caroline M. Hoxby, 2000. "Does Competition among Public Schools Benefit Students and Taxpayers?," American Economic Review, American Economic Association, vol. 90(5), pages 1209-1238, December.
  5. Jess Gaspar & Edward L. Glaeser, 1996. "Information Technology and the Future of Cities," Harvard Institute of Economic Research Working Papers 1756, Harvard - Institute of Economic Research.
  6. Edward L. Glaeser & Bruce Sacerdote, 2001. "The Social Consequences of Housing," Harvard Institute of Economic Research Working Papers 1915, Harvard - Institute of Economic Research.
  7. Todd R. Stinebrickner & Ralph Stinebrickner, 2005. "What Can Be Learned About Peer Effects Using College Roommates? Evidence From New Survey Data and Students from Disadvantaged Backgrounds," University of Western Ontario, Centre for Human Capital and Productivity (CHCP) Working Papers 20054, University of Western Ontario, Centre for Human Capital and Productivity (CHCP).
  8. Grinblatt, Mark & Keloharju, Matti & Ikäheimo, Seppo, 2003. "Interpersonal Effects in Consumption: Evidence from the Automobile Purchases of Neighbors," University of California at Los Angeles, Anderson Graduate School of Management qt69h2f7cv, Anderson Graduate School of Management, UCLA.
  9. Alejandro Gaviria & Steven Raphael, 2001. "School-Based Peer Effects And Juvenile Behavior," The Review of Economics and Statistics, MIT Press, vol. 83(2), pages 257-268, May.
  10. Anne C. Case & Lawrence F. Katz, 1991. "The Company You Keep: The Effects of Family and Neighborhood on Disadvantaged Youths," NBER Working Papers 3705, National Bureau of Economic Research, Inc.
  11. Zimmerman, David J., 1999. "Peer Effects in Academic Outcomes: Evidence From a Natural Experiment," Williams Project on the Economics of Higher Education DP-52, Department of Economics, Williams College.
  12. Charles F. Manski, 1993. "Identification of Endogenous Social Effects: The Reflection Problem," Review of Economic Studies, Oxford University Press, vol. 60(3), pages 531-542.
  13. Alberto Alesina & Reza Baqir & Caroline Hoxby, 2000. "Political Jurisdictions in Heterogeneous Communities," NBER Working Papers 7859, National Bureau of Economic Research, Inc.
  14. Bruce Sacerdote, 2000. "Peer Effects with Random Assignment: Results for Dartmouth Roommates," NBER Working Papers 7469, National Bureau of Economic Research, Inc.
  15. Caroline Hoxby, 2000. "Peer Effects in the Classroom: Learning from Gender and Race Variation," NBER Working Papers 7867, National Bureau of Economic Research, Inc.
  16. Gordon C. Winston, 1999. "Subsidies, Hierarchy and Peers: The Awkward Economics of Higher Education," Journal of Economic Perspectives, American Economic Association, vol. 13(1), pages 13-36, Winter.
  17. Michael Kremer, 1997. "How Much does Sorting Increase Inequality?," The Quarterly Journal of Economics, Oxford University Press, vol. 112(1), pages 115-139.
  18. Evans, William N & Oates, Wallace E & Schwab, Robert M, 1992. "Measuring Peer Group Effects: A Study of Teenage Behavior," Journal of Political Economy, University of Chicago Press, vol. 100(5), pages 966-991, October.
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