This technical paper presents the complete technical specification of the current version of the RE-GEM (Regional and Environmental General Equilibrium Model) for India. The document lists all the key structural and behavioural equations, providing a justification for the chosen model specification. In addition, a complete description is provided of the estimation methods and the sources of the Indian data used in the model; an aggregated version of the Indian regional Social Accounting Matrix we constructed is appended to this document. The object is to inform in the most detailed way possible researchers interested in building on the OECD’s modelling effort, and to provide a useful tool for informing the debate on the economics of environmental policy in developing countries ...