Article history: Received 20 June 2011 Available online 28 November 2013 JEL classification: C78 D43 L13

Article history: Received 3 June 2011 Available online 17 October 2013 JEL classification: C73 D83 O32

Article history: Accepted 26 September 2010 JEL classification: O31 O33 O41

As explained by Axelrod in his seminal work An Evolutionary Approach to Norms, punishment is a key mechanism to achieve the necessary social control and to impose social norms in a self-regulated society. In this paper, we distinguish between two enforcing mechanisms. i.e. punishment and sanction, focusing on the specific ways in which they favor the emergence and maintenance of cooperation. Th...

Article history: Received 18 September 2008 Received in revised form 11 February 2011 Accepted 21 February 2011 Available online 24 February 2011 JEL classification: C91 C92 PsycINFO classification: 3020 3900

In this paper, we use probabilistic methods of excursion theory for Lévy processes in order to value some exotic options in general exponential Lévy models. AMS 2000 Subject Classification : Primary: 60G51, 91B28, 91B70. JEL Classification: C13.

The United States and Iran as former allies turned into adversaries after the Islamic Revolution of 1979. Since then the United States has tried to contain Iran as a state considered to be a threat to the U.S. national security. The U.S. Congress has also acted in line with the administrations’ policies and in some cases directed the administration to take a tougher stance toward Iran. A review...

In repeated games with di®erential information on one side, the labelling \general case" refers to games in which the action of the informed player is not known to the uninformed, who can only observe a signal which is the random outcome of his and his opponent's action. Here we consider the problem of minimizing regret (in the sense ̄rst formulated by Hannan [8]) when the information available...

We show that any connected regular graph with d + 1 distinct eigenvalues and odd-girth 2d + 1 is distance-regular, and in particular that it is a generalized odd graph. 2010 Mathematics Subject Classification: 05E30, 05C50; JEL Classification System: C0