Who's Who in Networks - Wanted: The Key Group

Ballester, Calvo-Armengol, and Zenou (2006, Econometrica, 74/5, pp. 1403-17) show that in a network game with local payoff complementarities, together with global uniform payoff substitutability and own concavity effects, the intercentrality measure identifies the key player - a player who, once removed, leads to the optimal change in overall activity. In this paper we search for the key group in such network games, whose members are, in...