2024

ABSTRACT - Political polarization in the United States goes beyond divided opinions on key political issues, extending to realms of culture, lifestyle, and social identity once thought to be apolitical. Using a sample of 1 million Twitter bios, this study investigates how users’ partisan self-presentation on social media tends to include cultural as well as political markers. Representing the text in Twitter bios as semantic networks, the study reveals clear partisan differences in how users describe themselves, even on topics that seem apolitical. Consequently, active Twitter users’ political alignments can be statistically inferred from the non-political references in their bios, even in the absence of explicitly partisan language. These findings offer further evidence of partisan polarization that is aligned with lifestyle preferences. Further research is needed to determine if users are aware of that alignment, which might indicate the politicization of lifestyle preferences. The findings also suggest an under-recognized way social media can promote polarization, not through political discourse or argument, but simply in how users present culture and lifestyle preferences on those platforms.

 2023

ABSTRACT - How do groups maintain internal solidarity and closure without compromising their access to diverse networks? A long line of previous research suggests focusing on the boundary-spanning activities of “brokers” who bridge gaps in social structure. In many contexts, however, brokers are viewed with suspicion and distrust rather than rewarded for their diversity of interests. This article examines groups in which the theoretical deck is seemingly stacked against brokerage and toward parochialism: American-Italian mafia families. Through an institutional analysis of the mafia organization, I trace how ethnic and organizational closure led marginalized actors to seek alternative paths to enrichment beyond the family-controlled networks and industries. Using a historical network data set, I document a division of network labor in which ethnic outsiders— more than other actors—benefited as bridges between parochial organizations. This illuminates a broader paradox of social organization: while social closure is typically thought important because it increases the group’s power over individual members and reinforces boundaries, it can also undermine those same boundaries by pushing marginal actors to seek opportunities and connections outside the group.

Is Your Neighbor Your Friend? Scan Methods for Spatial Social Network Hotspot Detection

Co-authored with Xiaofan Liang, Joshua Baker, and Clio Andris

Transactions in GIS

ABSTRACT - GIS analyses use moving window methods and hotspot detection to identify point patterns within a given area. Such methods can detect clusters of point events such as crime or disease incidences. Yet, these methods do not account for connections between entities, and thus, areas with relatively sparse event concentrations but high network connectivity may go undetected. We develop two scan methods (i.e., moving window or focal processes), EdgeScan and NDScan, for detecting local spatial-social connections. These methods capture edges and network density, respectively, for each node in a given focal area. We apply methods to a social network of Mafia members in New York City in the 1960s and to a 2019 spatial network of home-to-restaurant visits in Atlanta, Georgia. These methods successfully capture focal areas where Mafia members are highly connected and where restaurant visitors are highly local; these results differ from those derived using traditional spatial hotspot analysis using the Getis–Ord Gi* statistic. Finally, we describe how these methods can be adapted to weighted, directed, and bipartite networks and suggest future improvements.

2022

ABSTRACT - How does material culture matter for institutions? Material objects are increasingly prominent in sociological research, but current studies offer limited insight for how material objects matter to institutional processes. We build on sociological insights to theorize aesthetic style, a shared pattern of material object presence and usage among a cluster of organizations in an institutional field. We use formal relational methods and a survey of material objects from religious congregations to uncover the aesthetic styles that are part of the “logics of god” in the United States’ Christian religious field. We argue aesthetic styles help structure an institutional field by spanning objects’ meanings across space and time, stabilizing objects’ authority, and demarcating symbolic boundaries. Our research provides a conceptual tool for understanding how objects bridge the material and symbolic dimensions of institutions and a methodological example for examining the meaning of objects across numerous organizations in an institutional field.

ABSTRACT - We clarify conditions under which two seemingly contradictory yet widely observed tendencies occur in cultural markets where amateur connoisseurs evaluate products—reinforcement of previous consensus and contradiction of that same consensus. We start from prior work’s insight that achieving “distinction” requires that evaluators display tastes demonstrating higher skills of discernment and standards that are acknowledged as legitimate by others. Based on this, we argue that evaluators reinforce prior evaluations of products to demonstrate that they share the same quality standards as their peers, but they selectively contradict prior evaluations by downgrading widely acclaimed products, because doing the latter makes the evaluator appear to have even more sophisticated tastes than their peers. We test this account using 1.66 million reviews from an online platform where amateur connoisseurs publicly evaluate beers. Our analyses support an endogenous model explaining why and when evaluators may contradict existing evaluations even though a group plausibly sharing the same quality standards may have established such evaluations in the first place.

ABSTRACT - While criminal organizations often feature hierarchical positions, scholars debate the extent to which networks of informal collaboration among criminals reflect such hierarchies. This research uses historical data on collaboration involving more than 700 criminals across 24 Italian-American Mafia families and applies network regression models and simulations to determine whether mafiosi of similar centrality-based status were more likely to be criminal associates than mafiosi of dissimilar status. Rather than forming vertical collaborations linking mafia members into a centralized, hierarchical network structure, we find that mafiosi collaborated disproportionately more with colleagues of similar status. While network centrality predicted tie formation, formal rank in an organizational chart generally did not. Knowledge simply of a covert organization’s formal structure may not translate to understanding “on-the-ground” collaborations.

2021

ABSTRACT - Goldberg and Stein (2018) present an innovative agent-based computational model that shows how cultural associations can diffuse through superficial interpersonal interactions. They counterintuitively argue that segmented networks—for example, those resembling “small worlds” with dense local clustering—inhibit rather than promote cultural diffusion. This finding is notable because it breaks with a long line of influential research showing that local clustering is crucial to diffusion in cases where behaviors and practices—including cultural beliefs—require multiple reinforcements in order to spread. Replicating Goldberg and Stein’s model, we find this result only holds consistently in settings approximating small-group interactions. In models with larger populations, and where cultural associations require repeated reinforcement through social observation, locally clustered small-world networks can promote global cultural variation as well as globally-connected networks, and sometimes do so better. The complex interactions among parameters that lead to this reversal in Goldberg and Stein’s model are instructive for theoretical models of interpersonal influence.

To Racketeer Among Neighbors: Spatial Features of Criminal Collaboration in the American Mafia

Co-authored with Clio Andris, Brittany N. Freelin, Xi Zhu, Bradley Hinger, and Hanzhou Chen

International Journal of Geographical Information Science

ABSTRACT - The American Mafia is a network of criminals engaged in drug trafficking, violence, and other illegal activities. Here, we analyze a historical spatial social network (SSN) of 680 Mafia members found in a 1960 investigatory dossier compiled by the U.S. Federal Bureau of Narcotics. The dossier includes connections between members who were “known criminal associates” and members are geolocated to a known home address across 15 major U.S. cities. Under an overarching narrative of identifying the network’s proclivities toward security (dispersion) or efficiency (ease of coordination), we pose four research questions related to criminal organizations, power, and coordination strategies. We find that the Mafia network is distributed as a portfolio of nearby and distant ties with significant spatial clustering among the Mafia family units. The methods used here differ from former methods that analyze the point pattern locations of individuals and the social network of individuals separately. The research techniques used here contribute to the body of non-planar network analysis methods in GIScience and can be generalized to other types of spatially-embedded social networks.

2020

ABSTRACT - Despite widespread feeling that public opinion in the United States has become dramatically polarized along political lines, empirical support for such a pattern is surprisingly elusive. Reporting little evidence of mass polarization, previous studies assume polarization is evidenced via the amplification of existing political alignments. This article considers a different pathway: polarization occurring via social, cultural, and political alignments coming to encompass an increasingly diverse array of opinions and attitudes. The study uses 44 years of data from the General Social Survey representing opinions and attitudes across a wide array of domains as elements in an evolving belief network. Analyses of this network produce evidence that mass polarization has increased via a process of belief consolidation, entailing the collapse of previously cross-cutting alignments, thus creating increasingly broad and encompassing clusters organized around cohesive packages of beliefs. Further, the increasing salience of political ideology and partisanship only partly explains this trend. The structure of U.S. opinion has shifted in ways suggesting troubling implications for proponents of political and social pluralism.

ABSTRACT - The authors use the timing of a change in Twitter’s rules regarding abusive content to test the effectiveness of organizational policies aimed at stemming online harassment. Institutionalist theories of social control suggest that such interventions can be efficacious if they are perceived as legitimate, whereas theories of psychological reactance suggest that users may instead ratchet up aggressive behavior in response to the sanctioning authority. In a sample of 3.6 million tweets spanning one month before and one month after Twitter’s policy change, the authors find evidence of a modest positive shift in the average sentiment of tweets with slurs targeting women and/or African Americans. The authors further illustrate this trend by tracking the network spread of specific tweets and individual users. Retweeted messages are more negative than those not forwarded. These patterns suggest that organizational “anti-abuse” policies can play a role in stemming hateful speech on social media without inflaming further abuse.

ABSTRACT - Specialized knowledge is increasingly central in modern information- and technology-oriented economies, yet we know surprisingly little about how this knowledge is organized. We trace the evolution of specialized knowledge at both the individual- and network-levels by analyzing email exchanges shared among members of a large tech professional community in New York City over seven years. We find a shift over time toward the emergence of an increasingly specialized ecology of knowledge and information. This division of knowledge is driven by the influx of new cohorts of participants with different knowledge and interests than those already there. Yet, even as individual contributors increasingly sort into specialized niches, the community as a whole remains robust in its ability to address topics of diverse concern. This study illustrates how new sources of data enable us to see with greater clarity the structures underpinning modern knowledge-based innovation clusters.

2018

ABSTRACT - Does acquaintanceship with gays and lesbians produce more accepting attitudes toward homosexuality and gay rights? While most scholars and laypeople would likely answer in the affirmative, previous work struggles to answer this question due to the difficulty in disentangling social influence from social selection. Using panel data from the 2006-2010 editions of the General Social Survey, this paper provides a conservative test of the contact hypothesis for gay acceptance. People who had at least one gay or lesbian acquaintance at baseline exhibited larger attitude changes at two- and four-year follow-ups with regard to support for same-sex marriage and moral acceptance of homosexuality. Furthermore, this contact effect extended even - and perhaps especially - to people who otherwise displayed more negative prior attitudes and lower propensities for gay and lesbian acquaintanceship.

2017

The Entrepreneur's Network and Firm Performance

Co-authored with Victor Nee and Lisha Liu

Sociological Science

ABSTRACT - Diverse organizational forms coexist in China’s market economy, adapting and evolving in intensely competitive production markets. We examine the networks of founding chief executive officers of private manufacturing firms in seven cities of the Yangzi River Delta region in China. Through sequence analysis of ties that entrepreneurs relied on for help in the founding and critical events of their businesses, we identify three discrete forms of network governance: traditional kin-based, hybrid nonkin, and rational capitalist. We find that in traditional kin-based network governance, structural holes are linked to higher returns on assets and returns on equity. By contrast, in the rational capitalist form, structural holes and higher firm performance are not linked. We thus show that the content of the tie matters critically in the relationship between structural holes and firm performance.

ABSTRACT - Criminal networks are thought to be biased toward decentralization and security rather than integration and efficiency. This article examines this tradeoff in a large-scale national criminal network spanning more than 700 members of 24 distinct American mafia families operating in the mid-20th century. Producing a novel network image of the American mafia as a set of highly differentiated yet intertwined islands of criminal activity, the analysis uncovers a small-world structure that allowed both for strong intragroup closure and high intergroup connectivity. This balance reflected a division of network labor in which integrative bridging connections were disproportionately concentrated among a small number of criminals. Furthermore, the criminals who held such bridging ties tended to be either low- or high-status - but not of middling status - within their respective organizations.

Endogenous Dynamics of Institutional Change

Co-authored with Victor Nee and Sonja Opper

Rationality and Society

[Lead article in special issue with commentaries from R. Solow, M. Ruef, A. Van de Rijt, C. Cameron and M. Macy, P. DiMaggio, and R. Calvert]

ABSTRACT - A parsimonious set of mechanisms explains how and under which conditions behavioral deviations build into cascades that reshape institutional frameworks from the bottom up, even if institutional innovations initially conflict with the legally codified rules of the game. Specifically, we argue that this type of endogenous institutional change emerges from an interplay between three factors: the utility gain agents associate with decoupling from institutional equilibria, positive externalities derived from similar decoupling among one's neighbors, and accommodation by state actors. Where endogenous institutional change driven by societal action is sufficiently robust, it can induce political actors to accommodate and eventually to legitimize institutional innovations from below. We provide empirical illustrations of our theory in two disparate institutional contexts - the rise of private manufacturing in the Yangzi delta region of China since 1978, focusing on two municipalities in that region, and the diffusion of gay bars in San Francisco in the 1960s and 1970s. We validate our theory with an agent-based simulation.

2015

Why Do Liberals Drink Lattes?

Co-authored with Yongren Shi and Michael Macy

American Journal of Sociology

Our summary for USAPP blog

ABSTRACT - Popular accounts of "lifestyle politics" and "culture wars" suggest that political and ideological divisions extend also to leisure activities, consumption, aesthetic taste, and personal morality. Drawing on a total of 22,572 pairwise correlations from the General Social Survey (1972-2010), the authors provide comprehensive empirical support for the anecdotal accounts. Moreover, most ideological differences in lifestyle cannot be explained by demographic covariates alone. The authors propose a surprisingly simple solution to the puzzle of lifestyle politics. Computational experiments show how the self-reinforcing dynamics of homophily and influence dramatically amplify even very small elective affinities between lifestyle and ideology, producing a stereotypical world of "latte liberals" and "bird-hunting conservatives" much like the one in which we live. 

2013

ABSTRACT - This article documents heterogeneous economic returns to military service that vary with the individual propensity to serve, even within a relatively privileged sample of mostly white high school graduates. Using a rich set of covariates from the Wisconsin Longitudinal Study, I estimate propensity scores for male respondents' likelihood of voluntary military enlistment or involuntary draft conscription. Then, I use recently developed HLM-based methods for causal inference to analyze systematic variation in veteran status' effect on later earnings as a function of these propensity scores. Among individuals with low propensities for military service, but not among others, veterans suffer large wage penalties. While this pattern applies to both voluntary enlisters and draftees, the timing of the wage penalty differs by mode of military entry. These effects are shown to correlate strongly with differences in educational attainment between veterans and nonveterans with low propensities for military service, suggesting the greater value of opportunities for human capital accumulation in the civilian sphere. 

ABSTRACT - Research on contemporary European politics has shown that immigrant population size is strongly associated with vote totals for anti-immigrant political parties. Competitive threat theories suggest that this association should be positive, whereas intergroup contact theories imply that it should be negative. A two-level analysis of vote totals for the French Front National (FRN) suggests that the direction of this association depends critically on the level of analysis. At the department (i.e., state or regional) level, large immigrant populations are associated with higher FRN vote totals. At the commune (i.e., town or city) level, however, large immigrant populations are instead associated with lower FRN vote totals. These findings challenge the conclusions of previous analyses of populist-right voting and provide further evidence that contact and threat dynamics often operate simultaneously, albeit at different levels.