Voting contagion: Modeling and analysis of a century of U.S. presidential elections

Social influence plays an important role in human behavior and decisions. Sources of influence can be divided as external, which are independent of social context, or as originating from peers, such as family and friends. An important question is how to disentangle the social contagion by peers from external influences. While a variety of experimental and observational studies provided insight into this problem, identifying the extent of contagion based on large-scale observational data with an unknown network structure remains largely unexplored. By bridging the gap between the large-scale complex systems perspective of collective human dynamics and the detailed approach of social sciences, we present a parsimonious model of social influence, and apply it to a central topic in political science—elections and voting behavior. We provide an analytical expression of the county vote-share distribution, which is in excellent agreement with almost a century of observed U.S. presidential election data. Analyzing the social influence topography over this period reveals an abrupt phase transition from low to high levels of social contagion, and robust differences among regions. These results suggest that social contagion effects are becoming more instrumental in shaping large-scale collective political behavior, with implications on democratic electoral processes and policies.

[1]  Dan Braha,et al.  Anticipating Economic Market Crises Using Measures of Collective Panic , 2015, PloS one.

[2]  Cameron Marlow,et al.  A 61-million-person experiment in social influence and political mobilization , 2012, Nature.

[3]  Nicholas A. Christakis,et al.  Cooperative behavior cascades in human social networks , 2009, Proceedings of the National Academy of Sciences.

[4]  R. Huckfeldt,et al.  Citizens, Politics and Social Communication: Information and Influence in an Election Campaign , 1995 .

[5]  Sinan Aral,et al.  Identifying Influential and Susceptible Members of Social Networks , 2012, Science.

[6]  Jean-Philippe Bouchaud,et al.  Spatial correlations in vote statistics: a diffusive field model for decision-making , 2010, 1003.2807.

[7]  Lucas Antiqueira,et al.  Analyzing and modeling real-world phenomena with complex networks: a survey of applications , 2007, 0711.3199.

[8]  Ann N. Crigler,et al.  Crosstalk: Citizens, Candidates, and the Media in a Presidential Campaign , 1996 .

[9]  Thomas C. Schelling,et al.  Dynamic models of segregation , 1971 .

[10]  Michal Kosinski,et al.  PERSONALITY PROCESSES AND INDIVIDUAL DIFFERENCES Divided We Stand: Three Psychological Regions of the United States and Their Political, Economic, Social, and Health Correlates , 2013 .

[11]  J. Candia,et al.  Effects Of Mass Media And Cultural Drift In A Model For Social Influence , 2006, physics/0611189.

[12]  R. W. Kulhavy,et al.  Personality differences across regions of the United States. , 1973, The Journal of social psychology.

[13]  J. S. Andrade,et al.  Brazilian elections: voting for a scaling democracy , 2003 .

[14]  A. Getis.  The Analysis of Spatial Association by Use of Distance Statistics , 2010 .

[15]  P. Moran,et al.  A test for the serial independence of residuals. , 1950, Biometrika.

[16]  M. Mobilia.  Does a single zealot affect an infinite group of voters? , 2003, Physical review letters.

[17]  Serge Galam,et al.  Local dynamics vs. social mechanisms: A unifying frame , 2005 .

[18]  Boleslaw K. Szymanski,et al.  Social consensus through the influence of committed minorities , 2011, Physical review. E, Statistical, nonlinear, and soft matter physics.

[19]  Stefan Grosskinsky Warwick,et al.  Interacting Particle Systems , 2016 .

[20]  N. Christakis,et al.  The Spread of Obesity in a Large Social Network Over 32 Years , 2007, The New England journal of medicine.

[21]  J. Sundquist.  Dynamics of the Party System: Alignment and Realignment of Political Parties in the United States , 1974 .

[22]  S. Galam,et al.  The role of inflexible minorities in the breaking of democratic opinion dynamics , 2007, physics/0703021.

[23]  Press, Party, and Presidency , 1982 .

[24]  Dan Braha,et al.  Predicting Economic Market Crises Using Measures of Collective Panic , 2011, ArXiv.

[25]  Timoteo Carletti,et al.  How to make an efficient propaganda , 2006 .

[26]  S. McClurg.  Indirect Mobilization , 2004 .

[27]  Marija Mitrovic,et al.  Universality in voting behavior: an empirical analysis , 2012, Scientific Reports.

[28]  S. Galam.  Heterogeneous beliefs, segregation, and extremism in the making of public opinions. , 2004, Physical review. E, Statistical, nonlinear, and soft matter physics.

[29]  D. Stau,et al.  Election results and the Sznajd model on Barabasi network , 2002 .

[30]  S. Galam.  Sociophysics: A Physicist's Modeling of Psycho-political Phenomena , 2012 .

[31]  B. Latané,et al.  From private attitude to public opinion: A dynamic theory of social impact. , 1990 .

[32]  David W. Nickerson.  Is Voting Contagious? Evidence from Two Field Experiments , 2008, American Political Science Review.

[33]  Michael Boss.  Economic theory of democracy , 1974 .

[34]  Damon Centola,et al.  The Spread of Behavior in an Online Social Network Experiment , 2010, Science.

[35]  José S. Andrade,et al.  Tactical Voting in Plurality Elections , 2010, PloS one.

[36]  S. Galam.  Stubbornness as an unfortunate key to win a public debate: an illustration from sociophysics , 2016 .

[37]  Harry Eugene Stanley,et al.  Non-consensus Opinion Models on Complex Networks , 2012, Journal of Statistical Physics.

[38]  J. S. Andrade,et al.  Scaling behavior in a proportional voting process. , 1999, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[39]  R. Sah,et al.  Social Osmosis and Patterns of Crime: A Dynamic Economic Analysis , 1988 .

[40]  S. Fortunato,et al.  Statistical physics of social dynamics , 2007, 0710.3256.

[41]  Robert D. Putnam,et al.  Bowling alone: the collapse and revival of American community , 2000, CSCW '00.

[42]  John Heppen.  Racial and Social Diversity and U.S. Presidential Election Regions , 2003, The Professional Geographer.

[43]  Boleslaw K. Szymanski,et al.  Evolution of Opinions on Social Networks in the Presence of Competing Committed Groups , 2011, PloS one.

[44]  Yaokun Wu,et al.  Opinion dynamics with stubborn vertices , 2012 .

[45]  Shlomo Havlin,et al.  Dynamic opinion model and invasion percolation. , 2009, Physical review letters.

[46]  Boleslaw K. Szymanski,et al.  Accelerating consensus on co-evolving networks: the effect of committed individuals , 2011, Physical review. E, Statistical, nonlinear, and soft matter physics.

[47]  N. Christakis,et al.  Dynamic spread of happiness in a large social network: longitudinal analysis over 20 years in the Framingham Heart Study , 2008, BMJ : British Medical Journal.

[48]  S. Redner,et al.  On the role of zealotry in the voter model , 2007 .

[49]  Angus Campbell,et al.  The American voter , 1960 .

[50]  P. Lazarsfeld,et al.  The People's Choice: How the Voter Makes Up His Mind in a Presidential Campaign , 1968 .

[51]  J. S. Andrade,et al.  Generalized Zipf's law in proportional voting processes , 2003 .

[52]  Dirk Helbing,et al.  Saving Human Lives: What Complexity Science and Information Systems can Contribute , 2014, Journal of statistical physics.

[53]  S. Fortunato,et al.  Scaling and universality in proportional elections. , 2006, Physical review letters.

[54]  P. Moran.  Notes on continuous stochastic phenomena. , 1950, Biometrika.

[55]  Nicola Perra,et al.  Social Phenomena: From Data Analysis to Models , 2015 .

[56]  Thomas W. Valente,et al.  Models and Methods in Social Network Analysis: Network Models and Methods for Studying the Diffusion of Innovations , 2005 .

[57]  R. Florida.  The Rise of the Creative Class : And How It's Transforming Work, Leisure, Community and Everyday Life , 2003 .

[58]  J. Bouchaud,et al.  Election Turnout Statistics in Many Countries: Similarities, Differences, and a Diffusive Field Model for Decision-Making , 2012, PloS one.

[59]  Asuman E. Ozdaglar,et al.  Opinion Fluctuations and Disagreement in Social Networks , 2010, Math. Oper. Res..

[60]  Haroldo V. Ribeiro,et al.  Engagement in the electoral processes: scaling laws and the role of the political positions , 2013, Physical review. E, Statistical, nonlinear, and soft matter physics.

[61]  Claudio J. Tessone,et al.  System size stochastic resonance in a model for opinion formation , 2004, cond-mat/0409620.

[62]  F. Schweitzer,et al.  SOCIAL IMPACT MODELS OF OPINION DYNAMICS , 2001 .

[63]  Filippo Palombi,et al.  Stochastic Dynamics of the Multi-State Voter Model Over a Network Based on Interacting Cliques and Zealot Candidates , 2013, 1309.0396.

[64]  S. Galam.  Minority opinion spreading in random geometry , 2002, cond-mat/0203553.

[65]  S. Galam.  Rational group decision making: A random field Ising model at T = 0 , 1997, cond-mat/9702163.

[66]  Yasufumi Shibanai,et al.  Effects of Global Information Feedback on Diversity , 2001 .

[67]  J. Ord,et al.  Local Spatial Autocorrelation Statistics: Distributional Issues and an Application , 2010 .

[68]  B. Latané.  The psychology of social impact. , 1981 .

[69]  T M Li Ge Te.  Interacting Particle Systems , 2013 .

[70]  Richard Johnston.  The Decline of American Political Parties, 1952–1988 Martin P. Wattenberg 3rd ed.; Cambridge: Harvard University Press, 1990, pp. xviii, 203The Loyalties of Voters: A Lifetime Learning Model Richard Rose and Ian McAllister London: Sage, 1990, pp. xiv, 219 , 1991, Canadian Journal of Political Science.

[71]  S. Galam.  Contrarian deterministic effects on opinion dynamics: “the hung elections scenario” , 2003, cond-mat/0307404.

[72]  Dan Braha,et al.  Global Civil Unrest: Contagion, Self-Organization, and Prediction , 2012, PloS one.

[73]  M. Felgueiras,et al.  Some results on Gaussian mixtures , 2014 .

[74]  B. Everitt,et al.  Finite Mixture Distributions , 1981 .

[75]  Stefan Thurner,et al.  Statistical detection of systematic election irregularities , 2012, Proceedings of the National Academy of Sciences.

[76]  Christopher Kenny,et al.  Political Participation and Effects from the Social Environment , 1992 .

[77]  Yaneer Bar-Yam,et al.  Moran model as a dynamical process on networks and its implications for neutral speciation. , 2010, Physical review. E, Statistical, nonlinear, and soft matter physics.

[78]  Giacomo Como,et al.  Opinion Fluctuations and Disagreement in Social Networks , 2010 .

[79]  D. Stauffer,et al.  Election results and the Sznajd model on Barabasi network , 2001, cond-mat/0111147.

[80]  D. S. Hillygus.  Campaign Effects on Vote Choice , 2010 .

[81]  T. Valente,et al.  Peers, schools, and adolescent cigarette smoking. , 2001, The Journal of adolescent health : official publication of the Society for Adolescent Medicine.

[82]  D. Zanette,et al.  Stochastic resonance in a model of opinion formation on small-world networks , 2001, cond-mat/0111289.

[83]  J. Bibby.  Politics, parties, and elections in America , 1987 .

[84]  R. Huckfeldt,et al.  The Social Calculus of Voting: Interpersonal, Media, and Organizational Influences on Presidential Choices , 2002, American Political Science Review.

[85]  S. Kotz,et al.  Statistical Size Distributions in Economics and Actuarial Sciences , 2003 .

[86]  Dan Braha,et al.  Dynamical Response of Networks Under External Perturbations: Exact Results , 2007, 0705.4607.

[87]  Margie E Lachman,et al.  Place matters: consensual features and regional variation in American well-being and self. , 2002, Journal of personality and social psychology.

[88]  Rodney E. Hero.  Faces of inequality : social diversity in American politics , 1998 .

[89]  A M Jones,et al.  Health, addiction, social interaction and the decision to quit smoking. , 1994, Journal of health economics.

[90]  S. Carpenter,et al.  Early-warning signals for critical transitions , 2009, Nature.

[91]  M. Wattenberg,et al.  The Decline of American Political Parties 1952-1994 , 1985 .

[92]  Robert Huckfeldt,et al.  Discussant Effects on Vote Choice: Intimacy, Structure, and Interdependence , 1991, The Journal of Politics.

[93]  Serge Galam,et al.  The Trump phenomenon, an explanation from sociophysics , 2016, 1609.03933.

[94]  A. Ozdaglar,et al.  Discrete Opinion Dynamics with Stubborn Agents , 2011 .

[95]  N. Boccara.  MODELS OF OPINION FORMATION: INFLUENCE OF OPINION LEADERS , 2007, 0704.1790.

[96]  Lynn Vavreck,et al.  The Mass Media and the Public's Assessments of Presidential Candidates, 1952–2000 , 2007, The Journal of Politics.

[97]  Robert Huckfeldt,et al.  Partisan Cues and the Media: Information Flows in the 1992 Presidential Election , 1998, American Political Science Review.

[98]  Maxi San Miguel,et al.  Is the Voter Model a model for voters? , 2013, Physical review letters.

[99]  M. G. Cosenza,et al.  Nonequilibrium transition induced by mass media in a model for social influence. , 2005, Physical review. E, Statistical, nonlinear, and soft matter physics.