nep-net New Economics Papers
on Network Economics
Issue of 2018‒12‒10
five papers chosen by
Pedro CL Souza
Pontifícia Universidade Católica do Rio de Janeiro

  1. Superstar Economists: Coauthorship Networks and Research Output By Hsieh, Chih-Sheng; König, Michael D.; Liu, Xiaodong; Zimmermann, Christian
  2. Heterogeneous Consumer Expectations and Monopoly Pricing for Durables with Network Externalities By Hattori, Keisuke; Zennyo, Yusuke
  3. Network Matching Efficiency along the Economic Cycle: Direct and Indirect Ties By Arnaud Herault; Eva Moreno Galbis; Francois-Charles Wolff
  4. Ethnic diversity in Peruvian schools: Disentangling peer and class composition effects By Nicolas Pazos Navarro
  5. Twitter versus Traditional News Media: Evidence for the Sovereign Bond Markets By Costas Milas; Theodore Panagiotidis; Theologos Dergiades

  1. By: Hsieh, Chih-Sheng (Chinese University of Hong Kong); König, Michael D. (Vrije Universiteit Amsterdam); Liu, Xiaodong (University of Colorado, Boulder); Zimmermann, Christian (Federal Reserve Bank of St. Louis)
    Abstract: We study the impact of research collaborations in coauthorship networks on research output and how optimal funding can maximize it. Through the links in the collaboration network, researchers create spillovers not only to their direct coauthors but also to researchers indirectly linked to them. We characterize the equilibrium when agents collaborate in multiple and possibly overlapping projects. We bring our model to the data by analyzing the coauthorship network of economists registered in the RePEc Author Service. We rank the authors and research institutions according to their contribution to the aggregate research output and thus provide a novel ranking measure that explicitly takes into account the spillover effect generated in the coauthorship network. Moreover, we analyze funding instruments for individual researchers as well as research institutions and compare them with the economics funding program of the National Science Foundation. Our results indicate that, because current funding schemes do not take into account the availability of coauthorship network data, they are ill-designed to take advantage of the spillover effects generated in scientific knowledge production networks.
    Keywords: coauthor networks, scientific collaboration, spillovers, key player, research funding, economics of science
    JEL: C72 D85 D43 L14 Z13
    Date: 2018–10
  2. By: Hattori, Keisuke; Zennyo, Yusuke
    Abstract: This paper studies the optimal pricing and diffusion of durable goods that exhibit positive network externalities, when consumers are heterogeneous in their expectations about future network sizes. We consider the existence of naive consumers, as well as of sophisticated consumers having fulfilled expectations. We find that the firm charges the sequential-diffusion pricing that makes sophisticated consumers function as early adopters, unless consumers quickly become bored with using the goods and/or unless the firm heavily discounts its future profits. We also compare the profitability of three possible pricing strategies with different commitment powers: fixed, responsive, and pre-announced pricing.
    Keywords: durable goods; network externalities; diffusion process; consumer naivete; dynamic pricing
    JEL: D21 D42 L12 L14
    Date: 2018–04–15
  3. By: Arnaud Herault (GRANEM, University of Angers); Eva Moreno Galbis (Aix-Marseille Univ., CNRS, EHESS, Centrale Marseille, AMSE); Francois-Charles Wolff (LEMNA, University of Nantes and INED)
    Abstract: There is a large consensus in the literature on the major role of social networks as a helpful instrument to find a job. In this paper, we study the social network matching rate along the economic cycle both from a theoretical and empirical perspective. Using the French Labor Force Survey for the period 2003-2012, we find that the relationship between the network matching rate based on direct ties and the job finding rate is decreasing and convex as predicted by our theoretical setup. Results are completely modified when we consider a measure of the network matching rate based on indirect ties related to the share of peers in a job. In this case, we find a linearly increasing relation between the network matching rate and the job finding rate. This underlines not only the heterogeneous ways through which network membership may influence the individuals’ performance on the labor market, but also the different behaviors of these driving factors along the economic cycle.
    Keywords: employment, network matching rate, direct and indirect ties, job finding rate, immigrants
    JEL: J24 J61 J15 A14 D85
    Date: 2018–11
  4. By: Nicolas Pazos Navarro
    Abstract: Academics have thought of many ways to reduce the gaps in academic achievement for ethnic minorities, one of which is through manipulating the classroom composition. Many studies show that there are positive spill-overs or peer effects of sharing space with better performing students (Sacerdote, 2001). However, other studies find that students from ethnic minorities tend to be negatively affected by ethnically diverse classes, either because of racial stereotypes or segregation (Steele and Aronson, 1995). This study applies Lee’s (2007) linear-in-means model with fixed effects to a sample of approximately 140 thousand students from a national education census in Peru to disentangle endogenous peer effects from contextual peer effects, while solving for self-selection and the reflection problem. The study focuses on the effects of ethnic diversity on Peruvian indigenous students. Results suggest that the effect of class composition on ethnically diverse classes is driven by two distinct and opposing channels, one related to abilities spill-overs and one to stereotypes and segregation. Endogenous peer effects are negative, possibly due to incentives faced by teachers and school directors to focus on better students and neglect the poorer performing ones, thus enlarging the gap between them. In terms of ethnic composition, results are heterogeneous: indigenous students benefit from a large proportion of similar peers, but the effect is the opposite for non-indigenous students. The study concludes that the current composition of the average Peruvian class is suboptimal, and a larger proportion of indigenous students could help reduce the current gaps in achievement due to ethnicity.
    Date: 2018
  5. By: Costas Milas (Management School, University of Liverpool, UK; Rimini Centre for Economic Analysis); Theodore Panagiotidis (Department of Economics, University of Macedonia, Greece; Rimini Centre for Economic Analysis); Theologos Dergiades (Department of International and European Studies, University of Macedonia, Greece; School of Science and Technology, International Hellenic University, Greece)
    Abstract: This paper compares news in Twitter with traditional news outlets and then emphasizes their differential impact on Eurozone's sovereign bond market for a homogeneous news topic. We find a two-way information flow between Twitter's “Grexit” tweets and the respective mentions in traditional news outlets. The influence of Twitter on the traditional news is consistently more prolonged, especially in high-activity periods. We also assess the differential impact of the two news sources on sovereign spreads over and above the impact of economic/financial fundamentals, namely measures of default risk, liquidity risk and global financial risk. Our focus is on the borrowing costs of Eurozone's periphery; for comparison reasons, we also consider France as a core Eurozone country. The effect of Twitter on the Greek sovereign spread is positive and of higher magnitude than that of traditional news outlets. Weak contagion effects are recorded primarily for the case of Portugal and Ireland.
    Keywords: Grexit, Twitter, Traditional news outlets, Sovereign spreads
    JEL: C10 G01 G12
    Date: 2018–12

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