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Michael Macy

Goldwin Smith Professor of Arts and Sciences

Michael Macy left the farm in Tennessee where he grew up to attend Harvard, where he received his B.A. and later Ph.D, along with an M.A. from Stanford. He is currently Goldwin Smith Professor of Arts and Sciences and Director of the Social Dynamics Laboratory at Cornell, where he has worked since 1997. With support from the National Science Foundation, the Department of Defense, and Google, his research team has used computational models, online laboratory experiments, and digital traces of device-mediated interaction to explore familiar but enigmatic social patterns, such as circadian rhythms, the emergence and collapse of fads, the spread of self-destructive behaviors, cooperation in social dilemmas, the critical mass in collective action, the spread of high-threshold contagions on small-world networks, the polarization of opinion, segregation of neighborhoods, and assimilation of minority cultures. Recent research uses 509 million Twitter messages to track diurnal and seasonal mood changes in 54 countries, and telephone logs for 12B calls in the UK to measure the economic correlates of network structure. His research has been published in leading journals, including Science, PNAS, American Journal of Sociology, American Sociological Review, and Annual Review of Sociology.


  • Collective action;
  • social control;
  • self-organizing group dynamics;
  • cognitive game theory;
  • social exchange theory;
  • computer simulation;
  • laboratory experiments

Current Research Interests

  • Why liberals drink lattes (with Daniel DellaPosta and Yongren Shi)
  • Using Twitter to study mobilization in Arab Spring (with Jon Kleinberg, Noona Oh, Michael Siemon, Silvana Toska, and Shaomei Wu, supported by NSF)
  • How random perturbations can make social dynamics more predictable (with Milena Tsvetkova)
  • Using social media to study the cultural and economic correlates of network structure (with Patrick Park and Bogdan State, supported by NSF)
  • Whether social media attenuate or reinforce social class boundaries (with David Grusky and Bogdan State)
  • Using an MMOG to study intergroup conflict and cooperation (with Dustin Chertoff and Milena Tsvetkova, supported by NSF)
  • The puzzle of “three degrees of influence” (with Chris Cameron)
  • Using Amazon book purchases to measure political and cultural polarization (with Fedor Dokshin and Yongren Shi)
  • Using online experiments to study the willingness to “pay it forward” (with Milena Tsvetkova, supported by NSF)

Selected Publications & Presentations

Why Do Liberals Drink Lattes? 
Daniel Della Posta, Yongren Shi, and Michael Macy
American Journal of Sociology, March, 2015

The Mesh of Civilizations in the Global Network of Digital Communication 
Bogdan State, Patrick Park, Ingmar Weber, and Michael Macy
PLOS ONE, May 29, 2015

The Social Contagion of Anti-Social Behavior 
Milena Tsvetkova and Michael Macy
Sociological Science, Feb. 10, 2015

Big Theory: A Trojan Horse for Economics? 
Michael Macy
Review of Behavioral Economics 2014

The Signal Importance of Noise 
Michael Macy and Milena Tsvetkova
Sociological Methods and Research 2015

Digital Footprints: Opportunities and Challenges for Social Research 
Scott Golder and Michael Macy
Annual Review of Sociology, Vol. 40, 2014

The Social Contagion of Generosity 
Milena Tsvetkova and Michael Macy
PLOS One Feb. 13, 2014: 9(2): e87275

Statistical Mechanics and Social Sciences 
Santo Fortunato, Michael Macy, Sidney Redner
Journal of Statistical Physics 2013, 151:1-8

Critical Phenomena in Complex Contagions 
Vladimir Barash, Chris Cameron, and Michael Macy
Social Networks 2012, 34:451-61

Diurnaland Seasonal Mood Vary with Work, Sleep and Daylength Across Diverse Cultures 
Scott Golder and Michael Macy
Science 2011, 333:1878-81

Small Worlds and Cultural Polarization
Andreas Flache and Michael Macy
Journal of Mathematical Sociology 2011, 34: 146-76

Local Convergence and Global Diversity: From Interpersonal to Social

Andreas Flache and Michael Macy
Journal of Conflict Resolution 2011, 55: 970-95

Network Diversity and Economic Development
Nathan Eagle, Rob Claxton, and Michael Macy
Science 2010, 328: 1029-1031

Computational Social Science
David Lazer et al.
Science 2009, 323: 712-723

The False Enforcement of Unpopular Norms
Rob Willer, Ko Kuwabara, and Michael Macy
American Journal of Sociology 2009, 115:451-490

Neighborhood Chance and Neighborhood Change
Arnout Van de Rijt, David Siegel, and Michael Macy
American Journal of Sociology 2009, 114:1166-80

Complex Contagions and the Weakness of Long Ties
Damon Centola and Michael Macy
American Journal of Sociology 2007, 113:702-34

Culture, Identity, and Structure in Social Exchange: A Web-based Trust Experiment in the U.S. and Japan
Kuwabara, K., R. Willer, M. Macy, R. Mashima, S. Terai, and T. Yamagishi
Social Psychology Quarterly, 2007, 70:461-79

Collective Action and the Empirical Content of Stochastic Learning Models
M. Macy and A. Flache
American Journal of Sociology, 2007, 112: 1546-54

“Actors do not behave or decide as atoms outside a social context ... Their attempts at purposive action are instead embedded in concrete, ongoing systems of social relations.”— Mark Granovetter