Model-based support of climate policy is scientifically challenging because climate change involves linked physical and social systems that operate on multiple levels: local, national, and international. As a result, models must employ some strongly simplifying assumptions. The most frequently used models typically assume hyper-rational and homogenous human behavior. These ensure tractability but, as a trade-off, abstract away the effects of less-than-rational decision-making and actor heterogeneity on domestic policy effectiveness and the influence of domestic constituents on international policy agreement. In this paper, we introduce a multi-level model framework, called ENGAGE, that relaxes some common modeling assumptions by adopting an agent-based approach. ENGAGE is styled after the Putnam two-level game, in which negotiators at the international level are constrained by the heterogeneous policy preferences and power of constituents at the domestic level. We proceed to provide a detailed description and demonstration of the prototype domestic-level module. Domestic actors include firms and households who function as agents within an evolutionary representation of economic growth, energy technology, and climate change. This allows an evaluation of policies that accounts for agent decision-making and social and technological change. Ultimately, we plan to use the ENGAGE model to simulate the two-way dynamic feedback between international agreements and domestic policy outcomes. © 2012 Elsevier Ltd.
Agent-based modeling of climate policy: An introduction to the ENGAGE multi-level model framework