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Oct. 17: Polarization and Secular Trends in U.S. Public Opinion

  • Knox Hall 207 606 West 122nd Street New York, NY, 10027 United States (map)

Polarization and Secular Trends in U.S. Public Opinion: The Role of Homophily and Selective Disclosure in Political Discussion Networks

WHEN: Monday, October 3, 2016, 12:00 - 1:40 p.m.

WHERE: Knox Hall, 606 W. 122nd Street, Room 207

U.S. public opinion over the last few decades has been characterized by a yawning divide between Democrats and Republicans and, according to most scholars, this polarization is greatly visible on moral issues. In contrast, we find that the sorting of political preferences along partisan lines accounts for public opinion dynamics exclusively in the economic and civil rights domains. However, when it comes to moral issues, and especially gay rights, the prominent trend is a collective shift toward more progressive opinions. This secular trend follows a classic S-shaped curve, typical of a diffusion process, in which Democrats are leading the pack, while Republicans adopt the same progressive views at a slower pace first, only to catch up later on.

What are the micro-level mechanisms that bring about these opinion changes? We hypothesize that mechanisms of homophily and selective disclosure in political discussion networks may explain the partisan lag in the diffusion curves, whereas the extraordinary pace of the change on gay rights may be due to the diminished segregation of openly gays and lesbians in people’s social networks. Taking these aspects into account, we will conclude the talk presenting the building blocks of a formal model of interpersonal influence that accounts for the different evolution of public opinion across issue domains.

Delia Baldassarri is Professor in the Department of Sociology at New York University. She holds courtesy appointments in the Wilf Family Department of Politics and in the Management and Organizations Department at the Stern School of Business. Professor Baldassarri earned a B.A. and a Ph.D. in Sociology and Social Research from the University of Trento, Italy (2003; 2006), and a Ph.D. in Sociology from Columbia University (2007). Previously, she started in 2007 as an Assistant Professor and later became an Associate Professor at Princeton University.

Professor Baldassarri’s research interests are in the fields of Economic Sociology, Political Sociology, Social Networks, and Analytical Sociology. Her current research projects include a book project, Centrifugal Politics, Crosscutting People, that investigates the demographic and social network bases of partisanship in American public opinion, and a study of the emergence of solidarity and cooperation in complex societies, focusing on the empirical case of ethnically heterogeneous communities.

Lunch will be provided. For inquires about Networks and Time, please contact coordinators Byungkyu Lee ( or Mark Hoffman (

Funding support for the Networks and Time Seminar Series is provided by the Paul F. Lazarsfeld Lecture Series, administered by INCITE, which features events and programming that embody and honor Lazarsfeld’s commitment to the improvement of methodological approaches that address concerns of vital cultural and social significance.