SPECIAL ISSUE： REGIONAL CONVERGENCE AND COORDINATED URBAN GROWTH Externalities, Transport Networks and the Economic Growth of Urban Clusters

利用网络分析工具和新经济地理理论对新古典区域经济增长模型进行修正,通过对交易费用的细分构建外部性和运输网络下的城市群经济增长模型,并利用1990-2008年中国部分城市数据和向量自回归模型（VAR）进行实证检验,得出以下结论。在运输网络影响下,中心城市依靠要素集聚获得增长,非中心城市快速接近中心城市。运输网络的改善,将加速中心城市的要素集聚。同时,在保留部分新增要素的情况下,增加节点集聚系数、降低非中心城市问的运输成本,利于非中心城市对外部性的应用,加速其经济增长,促进与中心城市的协同增长。因此,在建设交通运输基础设施时,不仅要重视非中心城市与中心城市的互联互通,更要重视非中心城市间的相互联结。     

Social networks and the organisation of big business groups in post New Economic Policy (NEP) era in the 1990s in Malaysia

Personal ties are generally regarded as important to big business growth in Malaysia, particularly after the New Economic Policy (NEP) in the 1990s. Common types are informal ones established between multi-ethnic big business people and Malay key state and political leaders. Other types of ties, company directorship links and informal ties, are seldom studied especially those between the business people and former state bureaucrats and corporate professionals. Thus, by conceptualising the directorship links and informal personal ties as social networks, the author conducted a sociological analysis of some intra- and inter-ethnic directorship links and ties established by four prominent big businessmen after the NEP in the 1990s. This article reports the main finding on the links and ties becoming a common organisational mechanism of business groups owned and controlled by the businessmen, besides providing access to the state. Therefore, another understanding of inter- and intra-ethnic personal ties in big business growth, especially after the NEP is achieved.     

Popularity breeds contempt: The evolution of reputational dislike relations and friendships in high school

In this study, we examined the dynamics of the perception of “dislike” ties (reputational dislike) among adolescents within the contexts of friendship, perceived popularity, substance use, and Facebook use. Survey data were collected from a longitudinal sample of 238 adolescents from the 11th and 12th grades in one California high school. We estimated stochastic actor-based network dynamic models, using reports of reputational dislike, friendships, and perceived popularity, to identify factors associated with the maintenance and generation reputational dislike ties. The results showed that high-status adolescents and more frequent Facebook users tended to become perceived as or stay disliked by their peers over time. There was a tendency for friendships to promote the creation and maintenance of reputational disliking but not vice versa. Adolescents tended to perceive others as disliked when their friends also perceived them as disliked. There was no evidence that either cigarette smoking or drinking alcohol affected reputational dislike dynamics. This study highlights the important role that the hierarchical peer system, online peer context, and friendships play in driving information diffusion of negative peer relations among adolescents.     

Bid-rigging networks and state-corporate crime in the construction industry

This study highlights the symbiotic relationship that may arise between political and business actors in conspiracies organized around public construction bids. Based on a core-periphery social network analysis, the study tracks the emergence of such a conspiracy in the city of Laval (Canada) by illustrating the evolution of bid-rigging networks revolving around suspected and persistent acts of corruption, bid-rigging, and bribery. To assess this process, the study monitors irregular bidding indicators across a data set compiled from more than 7000 public construction tenders that were processed by the city from 1966 to 2013. Findings reveal that firms suspected of bid-rigging activities were perennial core participants largely as a result of a state-corporate crime system that served as the guiding force for agreements between the main construction entrepreneurs.     

Analytic strategies for longitudinal networks with missing data

Missing data are often problematic when analyzing complete longitudinal social network data. We review approaches for accommodating missing data when analyzing longitudinal network data with stochastic actor-based models. One common practice is to restrict analyses to participants observed at most or all time points, to achieve model convergence. We propose and evaluate an alternative, more inclusive approach to sub-setting and analyzing longitudinal network data, using data from a school friendship network observed at four waves (N = 694). Compared to standard practices, our approach retained more information from partially observed participants, generated a more representative analytic sample, and led to less biased model estimates for this case study. The implications and potential applications for longitudinal network analysis are discussed.     

Social capital of entrepreneurs in a developing country: The effect of gender on access to and requests for resources

This paper addresses gender differences in the social capital of entrepreneurs in a developing country. Social networks are often an important asset for accessing resources; however, they may also be a liability in developing countries, since entrepreneurs are often expected to support their contacts. Using a recent survey among urban and rural Ugandan entrepreneurs, we focus on the financial resources that entrepreneurs can obtain from their contacts on the one hand, and requests for financial support made to the entrepreneurs from these contacts on the other hand. Our results show that there are gender differences associated with access to, and requests for, financial resources.     

Dynamic social media affiliations among UK politicians

Inter-personal affiliations and coalitions are an important part of politicians’ behaviour, but are often difficult to observe. Since an increasing amount of political communication now occurs online, data from online interactions may offer a new toolkit to study ties between politicians; however, the methods by which robust insights can be derived from online data require further development, especially around the dynamics of political social networks. We develop a novel method for tracking the evolution of community structures, referred to as ‘multiplex community affiliation clustering’ (MCAC), and use it to study the online social networks of Members of Parliament (MPs) and Members of the European Parliament (MEPs) in the United Kingdom. Social interaction networks are derived from social media (Twitter) communication over an eventful 17-month period spanning the UK General Election in 2015 and the UK Referendum on membership of the European Union in 2016. We find that the social network structure linking MPs and MEPs evolves over time, with distinct communities forming and re-forming, driven by party affiliations and political events. Without including any information about time in our model, we nevertheless find that the evolving social network structure shows multiple persistent and recurring states of affiliation between politicians, which align with content states derived from topic analysis of tweet text. These findings show that the dominant state of partisan segregation can be challenged by major political events, ideology, and intra-party tension that transcend party affiliations.     

In transit: Changing social networks of sub-Saharan African migrants in Turkey and Greece

Research on the role of social networks in human migration has mainly relied on single snapshots in time. This paper focuses on the changes in composition and usage of the transnational networks of migrants and why these changes occur. It is based on ethnography and network analysis with forty sub-Saharan African migrants in two transit contexts: Turkey and Greece, over a 17-month period. Findings show that relationship preferences, resources and communication infrastructures constitute an individual opportunity infrastructure affecting how critical events produce network changes. This process is ongoing through the continued experience of critical events, suggesting that the role of networks fluctuates over time.     

Personal networks typologies: A structural approach

Building typologies allows to compare networks on multiple dimensions, and to approach a generalization grounded on empirical data. In this article, we present a typology of personal networks only based on indicators related to the structure of relations between alters. It is designed from very detailed data on young French people who were involved in a longitudinal study. Our typology mobilizes a small number of indicators to discriminate the types that compose it. In so doing, we intend to make it applicable to various surveys.