11. Impact Analysis of the Economic Eastern Corridor on the Thai Economy: An Application of Multi-Regional Input–Output Model and Dynamic Computable General Equilibrium Model

To facilitate the multi-sectoral investment, the Thai government has initiated a new development project titled Eastern Economic Corridor (EEC), located in the eastern provinces, namely Chachoengsao, Rayong, and Chonburi. This project accommodates the construction of a new high-speed train and the extensions of existing seaports, highways, and airports. Also, investment promotion has been implemented, offering the tax incentive and other benefits to the targeted industries. This study aimed to quantitatively examine the economic impacts of the EEC project by utilizing two methods. First, the multi-regional input–output table (MRIO) and multiplier analysis were applied to investigate the cross-province and cross-region impacts. Second, based on the national Social Accounting Matrix (SAM), the dynamic Computable General Equilibrium (CGE) model was utilized for examining the inter-temporal effects. The result obtained from MRIO showed that investment expansion in the EEC area could induce cross-regional spillover, accounting for approximately 30% of GDP. The dynamic CGE model demonstrated that if the planned investments were continuously implemented, the GDP would consistently increase, resulting in an average household income rise of around 31% in 2034 compared to the base case. This study highlights the complementary use of two models to evaluate the multidimensional impacts of the EEC development project, including short-term spatial spillovers and long-term national effects.