Commentary Modeling international climate change negotiations more responsibly: Can highly simplified game theory models provide reliable policy insights? Kaveh Madani ⁎ Department of Civil, Environmental, and Construction Engineering, University of Central, Florida, Orlando, FL 32816, USA abstract article info Article history: Received 4 June 2012 Received in revised form 21 February 2013 Accepted 22 February 2013 Available online 2 April 2013 Keywords: Game theory Climate change Non-cooperative Conflict resolution Policy In a recent article in this journal entitled “Game Theory and Climate Diplomacy”, DeCanio and Fremstad (2013) provide an interesting treatment of a range of simple game theoretic characterizations of international climate negotiations. The authors use the Nash and Maxi-min stability definitions to analyze 25 two-by-two ordinal games, which they recognize as “possible game-theoretic characterizations of climate negotiations between two players (e.g., Great Powers or coalitions of states)”. The authors' main conclusion that the Prisoner's Di- lemma might not be the best description of climate negotiations game is consistent with the findings of others who have studied two-by-two conflicts over natural commons (Bardhan, 1993; Madani, 2010; Sandler, 1992; Taylor, 1987). Nevertheless, given the importance of the climate change issue, as well as the potential effects of our actions on the state of the environment and the well-being of future generations, I would like to address some gaps in their analysis, which result in it having limited usefulness for policy purposes. Of course, all models are simplified representations of reality, full of limitations. “Essentially, all models are wrong, but some are useful” (Box and Draper, 1987). So, “the practical question is how wrong do they have to be to not be useful” (Box and Draper, 1987). Models' limitations need to be carefully considered when interpreting them or applying their results to policy but some models are too simple to provide useful policy advice. © 2013 Elsevier B.V. All rights reserved. 1. Introduction: Reliability of Simple Game Theory As an analytical tool, game theory can enhance our understanding of real-world conflicts and provide valuable suggestions for policy de- velopment processes (Dietz and Zhao, 2011; Dinar et al., 2008; Finus, 2008; Heitzig et al., 2011; Howard, 2006; Madani, 2011; Wood, 2011). However, considerable simplifying assumptions can limit the applicability of game theory models to real world applications, which must be considered when modeling results are used to develop policies (Madani and Hipel, 2011; Wood, 2011). In my opinion, prescribing policy actions that can affect the state of nature and the well-being of billions of people around the globe must not rely on simple game models that ignore some essential characteristics of the problem. While simplifications are integral to modeling complex conflicts, the effects of simplifying assumptions on the modeling outputs should not be overlooked when interpreting the results. DeCanio and Fremstad (2013) (DF hereafter) use highly simplistic models to analyze climate change negotiations. While their analysis provides some useful insights, in my opinion the models they consider are too simple to be used in policy advice. This is despite the fact that the literature on “climate change and game theory” (Aldy et al., 2010; Asheim et al., 2006; Camerer and Thaler, 2003; Dutta and Radner, 2004, 2009; Finus, 2008; Froyn and Hovi, 2008; Heitzig et al., 2011; Levy et al., 2009; Pittel and Rübbelke, 2008; Rübbelke, 2011; Rubio and Ulph, 2006; Walker et al., 2007; Weikard et al., 2010; Wood, 2011) is fairly rich and has improved significantly over the last decade due to the importance of the climate change topic. Researchers have adopted game theory approaches that better reflect the reality of climate change negotiations and can suggest practical resolutions. In this commentary, I raise some fundamental questions about the key assumptions of DF's analysis, and briefly discuss alternative assump- tions and solution methods that could lead to more reliable and realistic policy insights. While my comments are specifically addressed to DF's article, they can be generalized to other game theory models of climate change and natural resources conflicts. Given the limited length of commentaries, the supporting analysis has been provided as an appen- dix. Readers interested in the background game theory science and methods may consult the provided references. 2. Question 1. Are Nash and Maxi-min Solution Concepts Appropriate for Climate Games? DF mainly rely on the Nash and Maxi-min solution concepts (stability definitions) for determining the equilibria (possible outcomes) of Ecological Economics 90 (2013) 68–76 ⁎ Tel.: +1 407 823 2317; fax: +1 407 823 3315. E-mail address: kmadani@ucf.edu. Contents lists available at SciVerse ScienceDirect Ecological Economics journal homepage: www.elsevier.com/locate/ecolecon 0921-8009/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.ecolecon.2013.02.011