Working Paper No. 617

Who's Who in Crime Networks. Wanted: The Key Player

Published: March 29, 2004Pages: 29Keywords: Social Networks; Crime; Centrality Measures; Key Group; PoliciesJEL-codes: A14; C72; K42

Who's Who in Crime Networks. Wanted: The Key Player Coralio Ballester, Antoni Calvó-Armengol and Yves Zenou

Criminals are embedded in a network of relationships. Social ties among criminals are modeled by means of a graph where criminals compete for a booty and benefit from local interactions with their neighbours. Each criminal decides in a non-cooperative way how much crime effort he will exert. We show that the Nash equilibrium crime effort of each individual is proportional to his equilibrium Bonacich-centrality in the network, thus establishing a bridge to the sociology literature on social networks. We then analyze a policy that consists of finding and getting rid of the key player, that is, the criminal who, once removed, leads to the maximum reduction in aggregate crime. We provide a geometric characterization of the key player identified with an optimal inter-centrality measure, which takes into account both a player's centrality and his contribution to the centrality of the others. We also provide a geometric characterization of the key group, which generalizes the key player for a group of criminals of a given size. We finally endogeneize the crime participation decision, resulting in a key player policy, which effectiveness depends on the outside opportunities available to criminals.


Sick of Inequality?

An Introduction to the Relationship between Inequality and Health

Sick of Inequality.jpg

In this book Andreas Bergh, Therese Nilsson, IFN and Lund University, and Daniel Waldenström, IFN and Paris School of Economics, France, review the latest research on the relationship between inequality and health. What does inequality mean for our health? Does increasing income inequality affect outcomes such as obesity, life expectancy and subjective well-being?


Seminars organized by IFN


To present ongoing research informal brown-bag seminars are held on Mondays at 11:30 am. This is an opportunity for IFN researchers to test ideas and results.

Academically oriented seminars are most of the time held on Wednesdays at 10 am. At these events researchers from IFN and other institutions present their research.

In addition, IFN organizes seminars open to the public. Topics for these are derived from the IFN research.

Research Institute of Industrial Economics, Grevgatan 34 - 2 fl, Box 55665, SE-102 15 Stockholm, Sweden | Phone: +46-(0)8-665 45 00 |