The problem of uncertainty in establishing causality (attribution) is substantial in the case of deforestation reduction projects due to high
potential for leakage (in the case of reserve protection) and to poor understanding of the social processes leading to deforestation (in the case of policy initiatives). This problem is likely to reduce substantially the carbon benefit that can be claimed under the CDM (Article 12) and in
many cases under Joint Implementation (Article 6) , but has much less potential effect on the credit that could be obtained under emissions
trading (Article 17) should tropical forest countries join Annex B of the Protocol.