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Key Players in Co-Offending Networks

  • Lindquist, Matthew
  • Zenou, Yves

We study peer effects in crime by analyzing co-offending networks. We first provide a credible estimate of peer effects in these networks equal to 0.17. This estimate implies a social multiplier of 1.2 for those individuals linked to only one co-offender and a social multiplier of 2 for those linked to three co-offenders. We then provide one of the first empirical tests of the key player policy in a real world setting. This policy defines a micro-founded strategy for removing the criminal from each network that reduces total crime by the largest amount. Using longitudinal data, we are able to compare the theoretical predictions of the key player policy with real world outcomes. By focusing on networks for which the key player has disappeared over time, we show that the theoretical predicted crime reduction is close to what is observed in the real world. We also show that the key player policy outperforms other reasonable police policies such as targeting the most active criminals or targeting criminals who have the highest betweenness or eigenvector centrality in the network. This indicates that behavioral-based policies can be more efficient in reducing crime than those based on algorithms that have no micro-foundation.

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Paper provided by C.E.P.R. Discussion Papers in its series CEPR Discussion Papers with number 9889.

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Date of creation: Mar 2014
Date of revision:
Handle: RePEc:cpr:ceprdp:9889
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  1. David Card & Laura Giuliano, 2013. "Peer Effects and Multiple Equilibria in the Risky Behavior of Friends," The Review of Economics and Statistics, MIT Press, vol. 95(4), pages 1130-1149, October.
  2. David R. Hunter & Mark S. Handcock & Carter T. Butts & Steven M. Goodreau & Martina Morris, . "ergm: A Package to Fit, Simulate and Diagnose Exponential-Family Models for Networks," Journal of Statistical Software, American Statistical Association, vol. 24(i03).
  3. Francesco Drago & Roberto Galbiati, 2010. "Indirect Effects of a Policy Altering Criminal Behaviour: Evidence from the Italian Prison Experiment," CSEF Working Papers 270, Centre for Studies in Economics and Finance (CSEF), University of Naples, Italy.
  4. Patacchini, Eleonora & Zenou, Yves, 2009. "Juvenile Delinquency and Conformism," CEPR Discussion Papers 7565, C.E.P.R. Discussion Papers.
  5. Sanjeev Goyal & Marco van der Leij & José Luis Moraga Gonzales, 2004. "Economics: An Emerging Small World?," CESifo Working Paper Series 1287, CESifo Group Munich.
  6. Leo Katz, 1953. "A new status index derived from sociometric analysis," Psychometrika, Springer, vol. 18(1), pages 39-43, March.
  7. Coralio Ballester & Antoni Calvo-Armengol & Yves Zenou, 2005. "Who's Who in Networks. Wanted: the Key Player," NajEcon Working Paper Reviews 666156000000000586,
  8. Hjalmarsson, Randi & Holmlund, Helena & Lindquist, Matthew, 2011. "The Effect of Education on Criminal Convictions and Incarceration: Causal Evidence from Micro-data," CEPR Discussion Papers 8646, C.E.P.R. Discussion Papers.
  9. Paul Goldsmith-Pinkham & Guido W. Imbens, 2013. "Social Networks and the Identification of Peer Effects," Journal of Business & Economic Statistics, Taylor & Francis Journals, vol. 31(3), pages 253-264, July.
  10. Lee, Lung-Fei & Liu, Xiaodong & Patacchini, Eleonora & Zenou, Yves, 2011. "Criminal Networks: Who is the Key Player?," CEPR Discussion Papers 8185, C.E.P.R. Discussion Papers.
  11. Patrick Bayer & Randi Hjalmarsson & David Pozen, 2007. "Building Criminal Capital behind Bars: Peer Effects in Juvenile Corrections," NBER Working Papers 12932, National Bureau of Economic Research, Inc.
  12. Calvó-Armengol, Antoni & Zenou, Yves, 2003. "Social Networks and Crime Decisions: The Role of Social Structure in Facilitating Delinquent Behaviour," CEPR Discussion Papers 3966, C.E.P.R. Discussion Papers.
  13. repec:oup:qjecon:v:120:y:2005:i:1:p:87-130 is not listed on IDEAS
  14. Gary S. Becker, 1968. "Crime and Punishment: An Economic Approach," Journal of Political Economy, University of Chicago Press, vol. 76, pages 169.
  15. Drago, Francesco & Galbiati, Roberto & Vertova, Pietro, 2007. "The Deterrent Effects of Prison: Evidence from a Natural Experiment," CEPR Discussion Papers 6401, C.E.P.R. Discussion Papers.
  16. repec:oup:qjecon:v:116:y:2001:i:2:p:655-679 is not listed on IDEAS
  17. Lung-fei Lee & Xiaodong Liu & Xu Lin, 2010. "Specification and estimation of social interaction models with network structures," Econometrics Journal, Royal Economic Society, vol. 13(2), pages 145-176, 07.
  18. Mastrobuoni Giovanni & Patacchini Eleonora, 2012. "Organized Crime Networks: an Application of Network Analysis Techniques to the American Mafia," Review of Network Economics, De Gruyter, vol. 11(3), pages 1-43, September.
  19. repec:oup:restud:v:60:y:1993:i:3:p:531-42 is not listed on IDEAS
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