@article{527267b580b4485ab0fabef908a72e07,
title = "Dynamics of evolving social groups",
abstract = "Exclusive social groups are ones in which the group members decide whether or not to admit a candidate to the group. Examples of exclusive social groups include academic departments and fraternal organizations. In this article, we introduce an analytic framework for studying the dynamics of exclusive social groups. In our model, every group member is characterized by his opinion, which is represented as a point on the real line. The group evolves in discrete time steps through a voting process carried out by the group's members. Due to homophily, each member votes for the candidate who is more similar to him (i.e., closer to him on the line). An admission rule is then applied to determine which candidate, if any, is admitted. We consider several natural admission rules including majority and consensus. We ask: How do different admission rules affect the composition of the group in the long run? We study both growing groups (where new members join old ones) and fixed-size groups (where new members replace those who quit). Our analysis reveals intriguing phenomena and phase transitions, some of which are quite counterintuitive.",
keywords = "Computational social choice, Price of anarchy, Social networks",
author = "Noga Alon and Michal Feldman and Yishay Mansour and Sigal Oren and Moshe Tennenholtz",
note = "Funding Information: The research of N. Alon was supported in part by ISF Grant No. 281/17, GIF Grant No. G-1347-304.6/2016, and the Simons Foundation. The work of M. Feldman was partially supported by the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013)/ERC Grant Agreement No. 337122 and by the Israel Science Foundation (Grant No. 317/17). The research of M. Tennenholtz was supported by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant No. 740435). Funding Information: The research of N. Alon was supported in part by ISF Grant No. 281/17, GIF Grant No. G-1347-304.6/2016, and the Simons Foundation. The work of M. Feldman was partially supported by the European Research Council under the European Union{\textquoteright}s Seventh Framework Programme (FP7/2007–2013)/ERC Grant Agreement No. 337122 and by the Israel Science Foundation (Grant No. 317/17). The research of M. Tennenholtz was supported by the European Research Council (ERC) under the European Union{\textquoteright}s Horizon 2020 research and innovation programme (Grant No. 740435). Authors{\textquoteright} addresses: N. Alon, Fine Hall, Princeton University, NJ, USA; email: nalon@math.princeton.edu; M. Feld-man and Y. Mansour, Blavatnik School of Computer Science Schreiber Building, Tel Aviv University, Tel Aviv, Israel; emails: michal.feldman@cs.tau.ac.il, mansour@post.tau.ac.il; S. Oren, Alon Building, Department of Computer Science, Ben-Gurion University of the Negev, Beer Sheva, Israel; email: sigal3@gmail.com; M. Tennenholtz, Bloomfield Building, Technion—Israel Institute of Technology, Haifa, Israel; email: moshet@ie.technion.ac.il. Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than ACM must be honored. Abstracting with credit is permitted. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from permissions@acm.org. {\textcopyright} 2019 Association for Computing Machinery. 2167-8375/2019/09-ART14 $15.00 https://doi.org/10.1145/3355948 Publisher Copyright: {\textcopyright} 2019 Association for Computing Machinery.",
year = "2019",
month = sep,
doi = "10.1145/3355948",
language = "English (US)",
volume = "7",
journal = "ACM Transactions on Economics and Computation",
issn = "2167-8375",
publisher = "Association for Computing Machinery (ACM)",
number = "3",
}