We investigate the computational complexity of several decision problems in hedonic coalition formation games and demonstrate that attaining stability in such games remains NP-hard even when they are additive. Precisely, we prove that when either core stability or strict core stability is under consideration, the existence problem of a stable coalition structure is NP-hard in the strong sense. ...

We investigate the computational complexity of several decision problems in hedonic coalition formation games and demonstrate that attaining stability in such games remains NP-hard even when they are additive. Precisely, we prove that when either core stability or strict core stability is under consideration, the existence problem of a stable coalition structure is NP-hard in the strong sense. ...

Article history: Received 1 November 2009 Available online 3 March 2011 JEL classification: D44 C63 C72 D82

Article history: Received 23 December 2008 Available online 18 January 2009 JEL classification: C70

Article history: Received 4 October 2010 Available online 9 November 2010 JEL classification: C70 C72 C73

Article history: Received 4 April 2013 Available online 27 November 2013 JEL classification: C70 D82

The class of maximin actions in general decision problems is characterized. JEL classification: C70, D81.

Article history: Received 20 June 2007 Available online 31 July 2010 JEL classification: C70 D82

Article history: Received 12 June 2012 Available online 13 February 2013 JEL classification: C70 C72

Article history: Received 6 February 2008 Accepted 14 May 2008 Available online 20 May 2008 JEL classification: C63 G11 G31 G39