players and spillovers to non-members. I introduce a sharing rule for coalition payoffs, called optimal sharing which … cartel if spillovers are negative. I introduce a new property, called non-essentiality and determine the set of stable … cartels under optimal sharing if spillovers are positive and if the non-essentiality property applies. Finally I analyse …

respect to the spatial spillovers of counterterror policy and another in which they are insensitive. We show that in the …

maximize it. Through the links in the collaboration network, researchers create spillovers not only to their direct coauthors …