In this issue we feature 6 current papers on the theme of social capital, chosen by Fabio Sabatini (Università degli Studi di Roma “La Sapienza”):

1. Social Connectedness in Urban Areas -   Michael Bailey; Patrick Farrell; Theresa Kuchler; Johannes Stroebel
2. Endogenous Social Connections in Legislatures - Marco Battaglini; Eleonora Patacchini; Edoardo Rainone
3. From Learning to Doing: Diffusion of Agricultural Innovations in Guinea-Bissau - Rute Martins Caeiro
4. The Consequences of Friendships: Evidence on the Effect of Social Relationships in School on Academic Achievement - Jason Fletcher; Stephen Ross; Yuxiu Zhang
5. Professional Networks and their Coevolution with Executive Careers - Nicoletta Berardi; Marie Lalanne; Paul Seabright
6. The role of distance and social networks in the geography of crowdfunding: evidence from France - Sylvain Dejean

1. Social Connectedness in Urban Areas - Michael Bailey; Patrick Farrell; Theresa Kuchler; Johannes Stroebel 

We use anonymized and aggregated data from Facebook to explore the spatial  structure of social networks in the New York metro area. We highlight the  importance of transportation infrastructure in shaping urban social networks  by showing that travel time and travel costs are substantially stronger  predictors of social connectedness between zip codes than geographic distance  is. We also document significant heterogeneity in the geographic breadth of  social networks across New York zip codes, and show that much of this  heterogeneity is explained by the ease of access to public transit, even  after controlling for socioeconomic characteristics of the zip codes' residents. When we group zip codes with strong social ties into hypothetical  communities using an agglomerative clustering algorithm, we find that  geographically non-contiguous locations are grouped into socially connected  communities, again highlighting that geographic distance is an imperfect  proxy for urban social connectedness. We also explore the social connections  between New York zip codes and foreign countries, and highlight how these are  related to past migration movements.

JEL: R1 R3 R4

Date: 2019?07

URL: http://d.repec.org/n?u=RePEc:nbr:nberwo:26029&r=soc

2. Endogenous Social Connections in Legislatures - Marco Battaglini; Eleonora Patacchini; Edoardo Rainone 

We present a model of the U.S. Congress in which social connections among  Congress members are endogenous and matter for their legislative activity. We  propose a novel equilibrium concept for the network formation game that  allows for a sharp characterization of equilibrium behavior and that yields a  unique prediction under testable conditions. While the equilibrium is  characterized by a large number of nonlinear equations, we show that the  model can be structurally estimated by an appropriately designed Approximate  Bayesian Computation method. Estimating the model using data from the 109th  to 113th U.S. Congresses, we show that social connections are important for  legislators' productivities and we identify some of the key determinants of  social centralities in Congress.

JEL: D71 D72

Date: 2019?06

URL: http://d.repec.org/n?u=RePEc:nbr:nberwo:25988&r=soc

3. From Learning to Doing: Diffusion of Agricultural Innovations in Guinea-Bissau - Rute Martins Caeiro

This paper analyzes the role of social networks in the diffusion of knowledge and adoption of cultivation techniques, from trainees to the wider community,  in the context of an extension project in Guinea-Bissau. In order to test for  social learning, we exploit a detailed census of households and social  connections across different dimensions. More precisely, we make use of a  village photo directory in order to obtain a comprehensive and fully mapped  social network dataset. We find evidence that agricultural information  spreads across networks from project participants to non-participants, with  different networks having different importance. The most relevant connection  is found to be between the network of people from which individuals would  ?borrow money?. We are also able to disentangle the relative importance of  weak and strong ties: in our context, weak ties are as important in the  diffusion of agricultural knowledge as strong ties. Despite positive  diffusion effects in knowledge, we found limited evidence of network effects  in adoption behavior. Finally, using longitudinal network data, we document  improvements in the network position of treated farmers over time.

JEL: O13 O31 O33 Q16

Date: 2019?07

URL: http://d.repec.org/n?u=RePEc:nbr:nberwo:26065&r=soc

4. The Consequences of Friendships: Evidence on the Effect of Social Relationships in School on Academic Achievement - Jason Fletcher (Robert M. La Follette School of Public Affairs, University of Wisconsin); Stephen Ross (University of Connecticut); Yuxiu Zhang (Genentech)

This paper examines the impact of youth friendship links on student's own  academic performance (grade point average) using the Add Health. We estimate  a reduced form, high dimensional fixed effects model of within cohort or  grade friendship links, and use this model to predict each student's number  of friends whose mothers have a four year college degree. The effects of  friendship links are identified using across-cohort, within school variation  in demographic composition of the student's cohort or grade. We find that  increases in number of friendship links with students whose mothers are  college educated raises grade point average among girls, but not among boys.

Additional analyses suggest a positive view of the school environment and a  perception of one's self as functioning well in that environment as possible  mechanisms. The effects are relatively broad based across students over  maternal education, racial and ethnic composition and across schools that  vary in demographic composition over the same variables.

JEL: I21 J13 R23

Keywords: Social Interactions; Friendships; Heterogeneous Peer Effects; Grades; Cohort Study; Non-Cognitive Effects

Date: 2019/07

URL: http://d.repec.org/n?u=RePEc:hka:wpaper:2019-043&r=soc

5. Professional Networks and their Coevolution with Executive Careers - Nicoletta Berardi; Marie Lalanne; Paul Seabright

This paper examines how networks of professional contacts contribute to the  development of the careers of executives of North American and European  companies. We build a dynamic model of career progression in which career  moves may both depend upon existing networks and contribute to the  development of future networks. We test the theory on an original dataset of  nearly 73 000 executives in over 10 000 firms. In principle professional  networks could be relevant both because they are rewarded by the employer and  because they facilitate job mobility. Our econometric analysis suggests that,  although there is a substantial positive correlation between network size and  executive compensation, with an elasticity of around 20%, almost all of this  is due to unobserved individual characteristics. The true causal impact of  networks on compensation is closer to an elasticity of 1 or 2% on average,  all of this due to enhanced probability of moving to a higher-paid job. And  there appear to be strongly diminishing returns to network size.

JEL: E02 E32 E62 F41 H20

Keywords: professional networks, labor mobility, executive compensation.

Date: 2019

URL: http://d.repec.org/n?u=RePEc:bfr:banfra:723&r=soc

6. The role of distance and social networks in the geography of crowdfunding: evidence from France - Sylvain Dejean (CE.RE.GE - CEntre de REcherche en GEstion - ULR - Universit? de La Rochelle - IAE Poitiers - Institut d'Administration des Entreprises (IAE) - Poitiers - Universite de Poitiers - Universite de Poitiers)

This article aims to estimate the cost of distance in the geographical flow  of crowdfunding, and to show how social ties between the 94 French  metropolitan regions shape the geography of funding. Our analysis draws upon  a unique database provided by the French leader in rewards-based  crowdfunding. The main result is that the elasticity of distance remains  important (around 0.5), and that social ties between regions determine the  flow of funding. Doubling the number of immigrants in a region increases the  number of investments by 24% and reduces the impact of distance.

Keywords: Crowdfunding,economic geography,social networks,gravity

Date: 2019?06?19

URL: http://d.repec.org/n?u=RePEc:hal:journl:hal-01645147&r=soc

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