Kyoto Project Mechanisms and Technology Diffusion

The paper deals with the diffusion of GHG mitigation technologies in developing countries. We develop a model where an abatement technology is progressively adopted by firms and we use it to compare the Clean Development Mechanism (CDM) with a standard Cap and Trade scheme (C&T). In the presence of learning spillovers, we show that the CDM yields a higher social welfare than C&T if the first adopter receives CDM credits whereas the followers don't. This result lends support to the policy proposal of relaxing the CDM additionality constraint for projects which generate significant learning externalities.