Inferring latent social networks from stock holdings

We infer the latent social networks of investors using data on their stock holdings. We map linkages to portfolio weights using a portfolio-choice model. The precision of an investor’s private signal about firm value is assumed to increase with his connections in the city where the firm is headquartered. Using money-manager data, we find that managerial linkages to a city are overly dispersed relative to the Erdös–Rényi model of i.i.d. connections. Managers at the tail of this distribution with non-i.i.d. linkages have more university alumni in that city. Their stock holdings there outperform their holdings in other cities.     

Network games with incomplete information

We consider a network game with strategic complementarities where the individual reward or the strength of interactions is only partially known by the agents. Players receive different correlated signals and they make inferences about other players’ information. We demonstrate that there exists a unique Bayesian-Nash equilibrium. We characterize the equilibrium by disentangling the information effects from the network effects and show that the equilibrium effort of each agent is a weighted combinations of different Katz–Bonacich centralities.     

Cultural embeddedness in supply networks

Recent studies on structural and relational embeddedness suggest that favorable position and connections in supply networks benefit a firm. While fruitful, this focus misses the motivations that prompt firms to take economic action in the first place. Understanding cultural embeddedness provides insight into why individuals and firms behave as they do and how their behavior can influence network structure. Contrary to the belief that firms act solely for profit and growth, we note that cultural contents such as values, social issues and political ideologies explain firms’ motives and guide their economic activities. We explore the role of cultural embeddedness through a grounded study of Country Natural Beef, a sustainability-oriented agricultural cooperative in the western United States. This supply network demonstrates strongly competing cultural claims among its members as well as a unique institutionalized culture. Cultural interactions at the node and network levels explain the functioning of and changes to the network. Through interviews, analysis of archival information and direct observation of pivotal events over a period of 5 years, we unpack cultural embeddedness and take an incremental step toward a theory of cultural embeddedness in cooperative supply networks.     

An empirical investigation of water consumption forecasting methods

Many regions on earth face daily limitations in the quantity and quality of the water resources available. As a result, it is necessary to implement reliable methodologies for water consumption forecasting that will enable the better management and planning of water resources. This research analyses, for the first time, a large database containing data from 2 million water meters in 274 unique postal codes, in one of the most densely populated areas of Europe, which faces issues of droughts and overconsumption in the hot summer months. Using the R programming language, we built and tested three alternative forecasting methodologies, employing univariate forecasting techniques including a machine-learning algorithm, with very promising results.     

Opportunities to reduce road traffic injury: new insights from the study of urban areas

Abstract

Over the past four decades considerable efforts have been taken to mitigate the growing burden of road injury. With increasing urbanisation along with global mobility that demands not only safe but equitable, efficient and clean (reduced carbon footprint) transport, the responses to dealing with the burgeoning road traffic injury in low- and middle-income countries has become increasingly complex. In this paper, we apply unique methods to identify important strategies that could be implemented to reduce road traffic injury in the Asia-Pacific region; a region comprising large middle-income countries (China and India) that are currently in the throes of rapid motorisation. Using a convolutional neural network approach, we clustered countries containing a total of 1632 cities from around the world into groups based on urban characteristics related to road and public transport infrastructure. We then analysed 20 countries (containing 689 cities) from the Asia-Pacific region and assessed the global burden of disease attributed to road traffic injury and these various urban characteristics. This study demonstrates the utility of employing image recognition methods to discover new insights that afford urban and transport planning opportunities to mitigate road traffic injury at a regional and global scale.     

Instagram and YouTube bloggers promote it,why should I buy? How credibility and parasocial interaction influence purchase intentions

Nowadays social network influencers play an important role in marketing by introducing products to their audience. In this article, we investigate the persuasion cues related to beauty and fashion influencers present on YouTube and Instagram. More precisely, we investigate how the para-social interaction (PSI) the audience creates with the online influencer, along with their perceived credibility, are related to the purchase intention and how they are, in turn, related to the social and physical attractiveness and attitude homophily. We base our research on four beauty influencers popular in France and control our results by the age of the participants and by the influencer. We find that attitude homophily is positively related to PSI but, surprisingly, the physical attractiveness shows negative relationship or no evidence of relationship. Both credibility of the influencers and PSI exhibit significant and positive relationships to purchase intention.     

A study on the deployment of high-speed broadband networks in NUTS3 regions within the framework of digital agenda for Europe

This paper investigates the high-speed broadband situation in the EU and its prospects. It uses a deployment model to estimate the investment required to meet the Digital Agenda for Europe (DAE) broadband targets set by the European Commission in its Europe 2020 strategy at different stages: as of 2016, after expected operators’ deployment, after public subsidies and leveraged investment, and as expected in 2020. The model uses data at the NUTS3 level, which is the most granular level that has data available on the status of broadband deployment, to arrive at a coherent and comparable framework. From the different perspectives on the investment to meet DAE targets, the paper concludes on the need for an appropriate combination of incumbent and alternative operators investments, public subsidies and leveraged investments, and new investments, both public and private and non-existing as of 2016, examining their feasibility and the impact of different regulatory, technical, and policy strategies.     

The Political Economy of Policy Vacuums: The European Commission on Demographic Change

ABSTRACT

Supranational organisations can only confront politico-economic issues that are recognised as important. Typically, issues gain recognition either when they provide an external shock to the system, shaking political actors into action, or when they are framed as important in policy networks concerned with developing the appropriate scientific approach. Ideally political and scientific actors align in creating pressures to recognise the issue as salient and to mobilise organisational responses. Issues differ in their capacity to be driven by both political and scientific pressures, creating crisis management, technocratic, and reform agenda outcomes. Here we explore a further variation, where pressures around an issue are insufficient, creating a policy vacuum. We examine one such policy vacuum in Europe: demographic change. This issue belongs to no particular Directorate-General in the European Commission, but is subject to policy frames from DG EMPL and DG ECFIN. Without sufficient political and scientific pressures, no particular policy position is occupied and advocated despite recognition of the issue’s importance. We discuss the role of policy vacuums and the need for their identification in political economy research.     

A simple model of homophily in social networks

Biases in meeting opportunities have been recently shown to play a key role for the emergence of homophily in social networks (see Currarini et al., 2009). The aim of this paper is to provide a simple microfoundation of these biases in a model where the size and type-composition of the meeting pools are shaped by agents׳ socialization decisions. In particular, agents either inbreed (direct search only to similar types) or outbreed (direct search to population at large). When outbreeding is costly, this is shown to induce stark equilibrium behavior of a threshold type: agents “inbreed” (i.e. mostly meet their own type) if, and only if, their group is above certain size. We show that this threshold equilibrium generates patterns of in-group and cross-group ties that are consistent with empirical evidence of homophily in two paradigmatic instances: high school friendships and interethnic marriages.