We study the extent to which personal connections among legislators influence abstentions in the U.S. Congress. Our analysis is conducted by observing representatives’ abstention for the universe of roll call votes held on bills in the 109th-113th Congresses. Our results show that a legislator’s propensity to abstain increases when the majority of his or her alumni connections abstains, even after controlling for other well-known predictors of abstention choices and a vast set of fixed effects. We further reveal that a legislator is more prone to abstain than to take sides when the demands from personal connections conflict with those of the legislator’s party.
This paper provides the first systematic analysis of migration to, within, and from Libya. The data used in the analysis are from the Displacement Tracking Matrix data set of the International Organization for Migration. The analysis uses this unique source of data, combining several techniques to analyze various dimensions of migration in Libya. First, the paper provides a detailed description of the demographic characteristics and national composition of the migrant populations in Libya. Next, it discusses the determinants of migration flow within Libya. The findings show that migration in Libya can be characterized as forced migration, because conflict intensity is the main determinant of the decision to relocate across provinces. Finally, the paper describes the direction, composition, and evolution of international migration flows passing through Libya and identifies the mechanisms of location selection by migrants within Libya by identifying hotspots and cluster provinces.
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Researchers often receive contrasting incentives when conducting their work. On the one hand, an interdisciplinary approach is required to produce scientific advances and access to funding. On the other, academic scholarships and evaluation mechanisms are still organized following the criteria of traditional disciplinary fields. If pursuing interdisciplinary research results in contrasting outcomes, science may face an interdisciplinarity dilemma: should researcher pursue their own private interest to build a reputation? Or should they endeavor towards public interest? How costly in terms of reputation is to choose interdisciplinarity research (IDR) over (more) specialized research?
We answer these questions by exploiting data on 23,926 articles published by 6,105 researchers affiliated with the University of Florida in the period 2008-2013. Through individual fixed-effect, we compare articles of the same scholar to roll out the influence of individual characteristics on the scientific impact of their research.
We find that the diverse dimensions of IDR (Variety, Balance, and Disparity) have a different effect on the reputation of a scholar and on her contribution to societal research. We confirm the existence of trade-off between private and public interest. We also point out that the increase of IDR aiming at connecting distant disciplines reduces the usefulness of the resulting knowledge. Results are robust to various specifications and apply to all scholars, regardless of their gender, collaboration behavior, discipline, and performance. These findings pose challenging questions to policymakers.
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The R package econet provides methods for estimating parameter-dependent network centrality measures with linear-in-means models. Both nonlinear least squares and maximum likelihood estimators are implemented. The methods allow for both link and node heterogeneity in network effects, endogenous network formation and the presence of unconnected nodes. The routines also compare the explanatory power of parameter-dependent network centrality measures with those of standard measures of network centrality. Benefits and features of the econet package are illustrated using data from Battaglini and Patacchini (2018), which examine the determinants of US campaign contributions when legislators care about the behavior of other legislators to whom they are socially connected.
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In this paper, we propose a model of national innovation production that formalizes the role of trade partnerships as a channel of knowledge spillovers across countries. The model is used to investigate the energy efficiency technological domain in the European Union (EU) using a panel database covering 19 EU countries for the time span 1990-2015. The model is estimated by using a new empirical strategy which allow to assess the knowledge spillover effects benefiting a country depending on its relative position in the trade network, and correct for common endogeneity concerns. We show that being central in the trade network is a significant determinant of a country’s innovative performance, and that learning-by-exporting is responsible for positive knowledge spillovers across countries. We further reveal that neglecting network effects may significantly reduce our understanding of domestic innovation patterns. Finally, we find that the benefits obtained from knowledge diffusion varies with the domestic absorptive capacity and policy mix composition. Our main implication is that policy mix design informed by network-based case studies could help maximizing the exploitation of positive knowledge spillovers.
This paper presents a new measure (the Diffusion Delay Centrality – DDC) to identify agents who should be put into isolation to decelerate a diffusion process spreading throughout a network. We show that DDC assigns a high rank to agents acting as the gatekeepers of the fringe of the network. We also show that the ranking of nodes obtained from the DDC is predicted by the difference in the values of betweenness and eigenvector centrality of network agents. The findings presented might constitute a useful tool to reduce diffusion processes both for policy makers and for corporate managers in the organization of production.
Using individual-level longitudinal data and geo-localized information on conflict-related violent events, we study the impact of conflict on health in the Gaza Strip. Results show that individuals living in localities exposed to more conflict events have a higher probability of suffering from a physical impairment and a chronic disease. The effect is larger for men and older individuals. Two mechanisms contribute to explain why living in conflict-affected area increases the incidence of physical impairment: conflict increases the difficulty to reach health facilities and it decreases individual income. The conflict-induced increase in the probability of having high blood pressure is instead consistent with the development of Post-Traumatic Stress Disorder (PTSD) due to the exposure to conflict-related violent events.
This paper generalizes the original Schelling (1969, 1971a,b, 2006) model of racial and residential segregation to a context of variable externalities due to social linkages. In a setting in which individuals’ utility function is a convex combination of a heuristic function à la Schelling, of the distance to friends, and of the cost of moving, the prediction of the original model gets attenuated: the segregation equilibria are not the unique solutions. While the cost of distance has a monotonic pro-status-quo effect, equivalent to that of models of migration and gravity models, if friends and neighbours are formed following independent processes the location of friends in space generates an externality that reinforces the initial configuration if the distance to friends is minimal, and if the degree of each agent is high. The effect on segregation equilibria crucially depends on the role played by network externalities.
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Little is known about the bargaining process of the Council of the European Union (EU), because negotiations of member countries occur behind closed doors. Using a brand-new dataset, we analyze the factors leading a country to a successful negotiation over one of the most important decisions taken by the Council every year, that for the allocation of the European budget. Important predictors of a country’s bargaining success, proxied by the quota of EU budget received, are the extent to which its votes are pivotal to form a winning coalition in the Council, its seniority, the control over the Council presidency office, and the political orientation of its government on the EU integration process. We also provide new evidence that countries advancing a similar policy agenda may benefit from each other’s effort. Finally, we demonstrate that the reforms of the Council introduced after 2004 had no significant impact on the bargaining process and the balance of power among member countries.