Key Player Policies When Contextual Effects Matter

Reprint No. 2014:50

Author(s): Coralio Ballester and Yves ZenouYear: 2014 Title: Journal of Mathematical Sociology Volume (No.): 38 (4) Pages: 233–248
Online article (restrictions may apply)

We consider a model where the criminal decision of each individual is affected by not only her own characteristics, but also by the characteristics of her friends (contextual effects). We determine who the key player is, i.e., the criminal who once removed generates the highest reduction in total crime in the network. We propose a new measure, the contextual intercentrality measure, that generalizes the one proposed by Ballester, Calvó-Armengol, and Zenou (2006 ) by taking into account the change in contextual effects following the removal of the key player. We also provide an example showing that the key player can be different whether contextual effects are taken into account or not. This means that the planner may target the wrong person if it ignores the effect of the “context” when removing a criminal from a network.

Ballester, Coralio and Yves Zenou (2014), "Key Player Policies When Contextual Effects Matter". Journal of Mathematical Sociology 38(4), 233–248.

Interdisciplinary European Studies

The European Union and the Return of the Nation State


This book explores the complex and ever-changing relationship between the European Union and its member states. The recent surge in tension in this relationship has been prompted by the actions of some member state governments as they question fundamental EU values and principles and refuse to implement common decisions seemingly on the basis of narrowly defined national interests.

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