Eli Berman (born 1960) is the Research Director for International Security Studies at the UC Institute on Global Conflict and Cooperation and since 2010 a Professor of economics at the University of California, San Diego. He is known for his work applying rational choice analysis to the behavior of radical religious groups. Research On violent radical religious groups Berman argues that economics can provide a significant insight into the vulnerabilities of radical and terrorist organizations, although not only because of the common assumption that cutting their funding is key to their defeat. Instead Berman says that "terrorist organizations are terribly vulnerable to defection, the same way that firms are vulnerable to workers stealing trade secrets, or just shirking on the job." He further argues that the economics of religion can provide explanations for the way in which "radical religious communities organize mechanisms to control defection in order to successfully conduct mutual aid—which they tend to be quite effective at." Using Laurence Iannaccone's theory of strict religious clubs (see club good theory), Berman argues that successful radical religious groups, such as Hamas, Hezbollah, Lashkar-e-Taiba, Mahdi Army and the Taliban, excel at providing social services to their members, while simultaneously filtering out "free riders"; Berman calls these movements "some of the most accomplished rebels of modern times." He further argues that the success of groups such as Hamas and al-Qaeda are more due to their organizational structures than their theology. By way of counter example he examines the case of the militant Jewish organisation Gush Emunim Underground, which ultimately over-reached its ability to sustain a group without defections, by carrying out attacks on civilians while neglecting to induce the necessary loyalty in its members and political base through various welfare measures. (Previous low-level violent vigilante activity, argues Berman, had been treated as a public good by Gush Emunim settlers.) Many commentators assume that people willing to join extremist groups are irrational, motivated only by extreme hate or abstract ideas of rewards in the afterlife. Contrary to these notions, Berman says that radical religious groups are rational in their selection of tactics. Berman does not see a dichotomy between insurgents and terrorists. He argues that they all belong to a single category he calls "rebels", and who, according to Berman, use a variety of techniques, depending on the circumstances, with suicide bombing being merely one end of the spectrum. Berman does not ascribe