Seminario: Social Network Games

Martedì 3 Settembre, ore 11:00 - Aula 1BC45 - Krzysztof R. Apt


Martedì 3 Settembre alle ore 11:00 in Aula 1BC45, Krzysztof R. Apt (CWI and University of Amsterdam, The Netherlands) terrà un seminario dal titolo: "Social Network Games"

In this lecture we survey our recent works on social network games. They are tailored to study a model of social networks introduced by Apt and Markakis in 2011 in which the nodes influenced by their neighbours can adopt one out of several products. In these games the payoff of each player weakly increases when more players choose his strategy, which is exactly opposite to the congestion games.
We show that such games may have no Nash equilibrium and that determining an existence of a Nash equilibrium is NP-complete. We also clarify the status and the complexity of the finite best response property (FBRP), the finite improvement property (FIP), and of a new property that we call the uniform FIP.
Further, we exhibit in this framework some paradoxes. One of them allows us to explain `bubbles' in a financial market, in which a decision of a trader to switch to some new financial product triggers a sequence of transactions, as a result of which all traders involved become worse off.

Based on joint works with Evangelos Markakis and Sunil Simon.

Short bio
K.R. Apt published four books and more than sixty journal articles, in computer science, mathematical logic and, more recently, economics.
His main current interest is in game theory and mechanism design.
Apt is a member of Academia Europaea. He is also the founder of the ACM Transactions on Computational Logic. This year he was a member of the Godel Prize committee. He is also involved in a number of open access initiatives.