The Linear Approximation of the CES Function to parameter estimation in CGE Modeling Author: Seyedhossein Sajadifar 1 Aram Arakelyan 2 Nasser khiabani 3 Abstract: In recent year, computable general equilibrium models have gained a considerable acceptance as a tool for economical policy analysis; however calibration of CGE model suffers from using elasticities from the econometrics literature. Some elasticities are contradictory and others are scarce functions such as the Cobb-Douglas, constant elasticities of substitution (CES), linear expenditure systems (LES) and others are typically used, but they constrain elasticities to be constant in addition, some critics question the robustness of calibrated functions because they are not statistically testable. This paper builds on recent work in macro-econometric estimation, developing an approach to parameter estimation for a widely employed CGE model. We introduce the Taylor approximation to the 2-input constant elasticity of substitution (CES) function approach to parameter estimation for computable general equilibrium (CGE) models. Also we estimate parameters for Cobb-Douglas production function. Key words: CES production function, Taylor approximation, translog function, Computable General Equilibrium. 1 - PhD student on specialty of Economics- Mathematical Methods and Modeling ( Yerevan State University) 2 - Doctor of Technical Sciences , Faculty of Mathematical Economics, Yerevan State University of Armenia 3 - PhD of economics , Institute for Management and Planning Studies, Iran 1