Information-sharing in social networks

We present a new model for reasoning about the way information is shared among friends in a social network and the resulting ways in which the social network fragments. Our model formalizes the intuition that revealing personal information in social settings involves a trade-off between the benefits of sharing information with friends, and the risks that additional gossiping will propagate it to someone with whom one is not on friendly terms but who is within oneʼs community. We study the behavior of rational agents in such a situation, and we characterize the existence and computability of stable information-sharing configurations, in which agents do not have an incentive to change the set of partners with whom they share information. We analyze the implications of these stable configurations for social welfare and the resulting fragmentation of the social network.     

Do Parental Networks Pay Off? Linking Children's Labor‐Market Outcomes to Their Parents' Friends

In this paper, we examine whether children are better off if their parents have more elaborate social networks. Using data on high‐school friendships of parents, we analyze whether the number and characteristics of friends affect the labor‐market outcomes of children. While parental friendships formed in high school appear long lasting, we find no significant impact on their children's occupational choices and earnings prospects. These results do not change when we account for network endogeneity, network persistency, and network measurement error. Only when children enter the labor market do friends of parents have a marginally significant but small influence on their occupational choice.     

Anti-coordination and social interactions

This paper studies the first model of social interactions with anti-coordination. Agents have fixed partners with whom they play a common bilateral game of anti-coordination, like the chicken game. Partnerships are represented as links of a network. The paper asks: How do social interactions interplay with the incentives to anti-coordinate? How does the social network affect individual choices in equilibrium? The analysis shows that network effects are much stronger than when partners play a coordination game. The network notably affects how agents respond when a strategy becomes more advantageous. In the standard benchmark of complete interactions, more agents play the strategy. This result does not generally hold when the network is incomplete. On bipartite networks, agents' choices are unaffected, while on core-periphery networks, less agents may play the strategy.     

Social network and private provision of public goods

Using a simple model with interdependent utilities, we study how social networks influence individual voluntary contributions to the provision of a public good. Departing from the standard model of public good provision, we assume that an agent’s utility has two terms: (a) ‘ego’-utility derived from the agent’s consumption of public and private goods, and (b) a social utility which is the sum of utility spillovers from other agents with whom the agent has social relationships. We establish conditions for the existence of a unique interior Nash equilibrium and describe the equilibrium in terms of network characteristics. We show that social network always has a positive effect on the provision of the public good. We also find that, in networks with “small world”-like modular structures, ‘bridging’ ties connecting distant parts of social network play an important role inducing an agent’s contribution to public good. Assumptions and results of the model are discussed in relation to the role of social capital in community-level development projects and to the effect of innovation networks on firms’ R&D investments.     

Communication in repeated network games with imperfect monitoring

I consider repeated games with private monitoring played on a network. Each player has a set of neighbors with whom he interacts: a player's payoff depends on his own and his neighbors' actions only. Monitoring is private and imperfect: each player observes his stage payoff but not the actions of his neighbors. Players can communicate costlessly at each stage: communication can be public, private or a mixture of both. Payoffs are assumed to be sensitive to unilateral deviations. First, for any network, a folk theorem holds if some Joint Pairwise Identifiability condition regarding payoff functions is satisfied. Second, a necessary and sufficient condition on the network topology for a folk theorem to hold for all payoff functions is that no two players have the same set of neighbors not counting each other.     

Bayesian learning in social networks

We extend the standard model of social learning in two ways. First, we introduce a social network and assume that agents can only observe the actions of agents to whom they are connected by this network. Secondly, we allow agents to choose a different action at each date. If the network satisfies a connectedness assumption, the initial diversity resulting from diverse private information is eventually replaced by uniformity of actions, though not necessarily of beliefs, in finite time with probability one. We look at particular networks to illustrate the impact of network architecture on speed of convergence and the optimality of absorbing states. Convergence is remarkably rapid, so that asymptotic results are a good approximation even in the medium run.     

Gender differences in social capital investment: Theory and evidence

This paper analyses individual social capital investment by extending the investment model of Glaeser et al. (2002) to allow for differing types of social capital. A dynamic solution to the individual's maximisation problem illustrates differences in social capital investment dependent on the conversion factor of investment. An empirical section finds that females invest more and derive greater wellbeing from this type of social capital investment; consistent with a higher conversion factor. The findings have implications for the work–life balance policies within firms and provide another explanation for gender differences in earnings.     

Methods of pricing common property use and some implications for optimal child-bearing and the social discount rate

Each individual consumes a numeraire capital-consumption good, harvests “fish” from a common property resource, and makes child-bearing and capital bequest decisions in her one-period life. The model is developed in a way that traces the physical impacts of harvest choices across generations. Consistent with previous results in models with pollution, it is shown that the efficient resolution of the stock externality can be accomplished by a combination of Pigouvian harvest and a child-bearing tax. Results are extended to show that the creation of asset-like individual transferable quotas (ITQs) induces efficient harvest and child-bearing decisions without a child-bearing tax. Clarifying previous results, it is shown that the social discount rate is equal to the common net-of-Pigouvian-tax rate of return on capital in both industries.     

Who you are or whom you know? Consumption interdependences in social networks

This paper presents an analysis of whether a consumer's decision to switch from one mobile phone provider to another is driven by individual consumer characteristics or by actions of other consumers in her social network. Such consumption interdependences are estimated using a unique dataset, which contains transaction data based on anonymized call records from a large European mobile phone carrier to approximate a consumer's social network. Results show that network effects have an important impact on consumers’ switching decisions: switching decisions are interdependent between consumers who interact with each other and this interdependence increases in the closeness between two consumers as measured by the calling data. In other words, if a subscriber switches carriers, she is also affecting the switching probabilities of other individuals in her social circle. The paper argues that such an approach is of high relevance to both switching of providers and to the adoption of new products.     

SOCIAL NORMS,LOCAL INTERACTION,AND NEIGHBORHOOD PLANNING*

This article examines optimal social linkage when each individual's repeated interaction with each of his neighbors creates spillovers. Each individual's discount factor is randomly determined. A planner chooses a local interaction network or neighborhood design before the discount factors are realized. Each individual then plays a repeated Prisoner's Dilemma game with his neighbors. A local trigger strategy equilibrium (LTSE) describes an equilibrium in which each individual conditions his cooperation on the cooperation of at least one “acceptable” group of neighbors. Our main results demonstrate a basic trade‐off in the design problem between suboptimal punishment and social conflict. Potentially suboptimal punishment arises in designs with local interactions since in this case monitoring is imperfect. Owing to the heterogeneity of discount factors, however, greater social conflict may arise in more connected networks. When individuals' discount factors are known to the planner, the optimal design exhibits a cooperative “core” and an uncooperative “fringe.”“Uncooperative” (impatient) types are connected to cooperative ones who tolerate their free riding so that social conflict is kept to a minimum. By contrast, when the planner knows only the ex ante distribution over individual discount factors, then in some cases the optimal design partitions individuals into maximally connected cliques (e.g., cul‐de‐sacs), whereas in other cases incomplete graphs with small overlap (e.g., grids) are possible.     

Does local social capital deter labour migration? Evidence from rural China

This article empirically investigates the effect of local social capital on job-related migration in rural China. A household’s social ties in the region of origin, which we refer to as local social capital, may deter migration, because local social capital is location specific and an individual cannot benefit from it if s/he migrates. In view of Chinese gift-giving culture, we use household expenses on wedding gifts for family members outside household, relatives and friends as a proxy for local social networks. Based on the data from the China Health and Nutrition Survey, we find that in rural China local social networks have a significantly negative effect on migration. The IV results suggest that a 10% increase in wedding gifts expenses results in roughly a 1.1 percentage points decrease in migration probability.     

Social cooperatives,social welfare associations and social networks

We use an original data-set to study how participation in two types of non-profit organizations – i.e. social welfare associations and social cooperatives – affects individual social capital, understood as a network of cooperative relationships. Participation in both the types of organization allows members to start new social relations. However, social welfare associations seem to play a significantly greater role in the development of volunteers’ social capital, favouring the creation of weak ties that are used to exchange information and advice, and offering the opportunity to establish stronger ties entailing concrete mutual support. Within social cooperatives, workers appear to develop their individual social capital to a greater extent than volunteers. Our results suggest that the composition of the workforce, the depth of members’ involvement in the organization’s activities and the human resources strategies adopted by the management influence the creation of cooperative relations through on-the-job interactions.     

Expanding the two wings of social capital for value creation: strategic entrepreneurship of HTC, 1997–2008

This study draws on a historical, qualitative case study to explore how a leading Taiwanese high-tech mobile phone manufacturer, HTC, successfully and continuously manoeuvred the two wings of social capital – that is, structural social capital and cognitive social capital – to create value in its strategic entrepreneurial process between 1997 and 2008. Taiwan is a wide-spreading trust-based Chinese Confucian-influenced culture. The process of developing trust-based social capital for value creation consists of three central actions: identifying potential social capital, reinforcing cognitive social capital, and extending structural social capital. Our findings advance knowledge of trust-based social capital based on the perspective of strategic entrepreneurship for value creation and offer practical implications for the mobilisation of social capital. In sum, we suggest that firms could develop trust-based social capital considering business conditions to reduce possible risks or uncertainties of network management in an international arena.     

Reciprocity in evolving social networks

We study the viability of conditional cooperation in a dynamically evolving social network. The network possesses the small world property, with high clustering coefficient but low characteristic path length. The interaction among linked individuals takes the form of a multiperson prisoners’ dilemma, and actions can be conditioned on the past behavior of one’s neighbors. Individuals adjust their strategies based on performance within their neighborhood, and both strategies and the network itself are subject to random perturbation. We find that the long-run frequency of cooperation is higher under the following conditions: (i) the interaction radius is neither too small nor too large, (ii) clustering is high and characteristic path length low, (iii) the mutation rate of strategies is small, and (iv) the rate of adjustment in strategies is neither too fast nor too slow.

Alternating-Offer Bargaining with Two-Sided Incomplete Information

I study alternating-offer bargaining games with two-sided incomplete information about the players' discount rates. For both perfect Bayesian equilibrium and a rationalizability-style notion, I characterize the set of expected payoffs which may arise in the game. I also construct bounds on agreements that may be made. The set of expected payoffs is easy to compute and incorporate into applied models. My main result is a full characterization of the set of perfect Bayesian equilibrium payoffs for games in which the distribution over the players' discount rates is of wide support, yet is in a weak sense close to a point mass distribution. I prove a lopsided convergence result: each player cannot gain from a slight chance that she is a strong type, but the player can suffer greatly if there is a slight chance that she is a weak type.     

VOTING AND SOCIAL PRESSURE UNDER IMPERFECT INFORMATION

We develop a model in which costly voting in a large, two‐party election is a sequentially rational choice of strategic, self‐interested players who can reward fellow voters by forming stronger ties in a network formation coordination game. The predictions match a variety of stylized facts, including explaining why an individual's voting behavior may depend on what she knows about her friends' actions. Players have imperfect information about others' voting behavior, and we find that some degree of privacy may be necessary for voting in equilibrium, enabling hypocritical but useful social pressure. Our framework applies to any costly prosocial behavior.     

社会资本的治理机制——以硅谷风险投资为例

本文以硅谷高新技术产业集群中的风险投资为背景,在分析硅谷中社会网络的结构以及社会资本构成的基础上,探讨了在风险投资中企业治理过程中,社会资本的治理作用与机制。提出硅谷中风险投资网络和社会资本特征能有效地减少交易成本,有利于信息的扩散以及知识和技术的溢出,特别是社会资本独特的治理机制创造了有利于自我实施模式实现的治理环境,促进了技术创新,推动了整个产业集群的发展。     

The role of social capital in the labour market in China1

Social capital is considered to play an economic role in labour markets. It may be particularly pertinent in one that is in transition from an administered to a market‐oriented system. One factor that may determine success in the underdeveloped Chinese labour market is thus guanxi, the Chinese variant of social capital. With individual‐level measures of social capital, we test for the role of guanxi using a dataset designed for this purpose, covering 7,500 urban workers and conducted in early 2000. The evidence is consistent with the basic hypothesis. Both measures of social capital – size of social network and Communist Party membership – have significant and substantial coefficients in the income functions. Social capital can have influence either in an administered system or in one subject to market forces. It appears to do so in both parts of the labour market.     

When sociable workers pay off: Can firms internalize social capital externalities?

We use an endogenous growth model to contrast the socially optimal allocation of human capital with the decentralized solution, in a context where workers make the choices that determine social capital accumulation. As social capital is expected to increase productivity but is not traded in markets, a positive social capital externality is identified. We discuss the possibility that, in response to this externality, firms subsidize social capital accumulation activities, incurring into additional costs that are recouped through productivity gains. This reaction by firms may be seen as a justification for some corporate social responsibility actions targeted at workers, although a full internalization of the externality does not look achievable in practice.     

高管个人社会资本与企业绩效之间的关系实证分析

本文收集并整理了357份调查问卷,并根据这些有效数据构建了结构方程模型,对高管的个人社会资本及它与企业绩效两者之间的关系进行了理论分析和实证研究.通过对实证结果分析可知,企业内部环境和外部环境下的社会资本是企业高管个人社会资本的组成部分;高管个人的社会资本与企业绩效之间存在并不显著的因果关系,只能通过企业适应能力显著影响企业的经济绩效.此研究结果是对已有研究结论的扩展及融合,证实了高管个人社会资本在整体上对企业绩效有着显著促进作用,同时也明确了高管个人社会资本与企业绩效间的作用路径.