WITCH is an energy-economy-climate model developed by the climate change group at FEEM. The model has been extensively used in the past 3 years for the economic analysis of climate change policies. WITCH is a hybrid top-down economic model with a representation of the energy sector of medium...

In this paper we argue that when a subgroup of countries cooperate on emission reduction, the optimal response of non-signatory countries reflects the interaction between three potentially opposing factors, the incentive to free-ride on the benefits of cooperation, the incentive to expand the...

This paper analyses the incentives to participate in and the stability of international climate coalitions. Using the integrated assessment model WITCH, the analysis of coalitions' profitability and stability is performed under alternative assumptions concerning the pure rate of time preference,...