Characterizing Supply-Side Drivers of Structural Change in the Construction of Economic Baseline Projections

A recent review of common modelling practices conducted during the Workshop "Shaping long-term baselines with Computable General Equilibrium (CGE) models" held at OECD in January 2018 showed that models include different assumptions on changes to the production function along their dynamic baselines. These changes imply shifts in sectoral compositions for the projected economies (i.e. structural change). This paper reviews the assumptions made by 24 modeling teams about supply-side drivers of structural change: primary factor efficiency and changes in input-output structures of the production function over time. We critically review various methodologies, identifying state-of-the-art practices, and we propose simple guidelines, particularly focusing on consistency between data sources and models. The review highlights that most models take into account structural change to some extent. However, more effort is needed in modelling projected changes in input-output structures. Furthermore, this review is helpful for understanding the functioning of dynamic CGE models and in assisting dynamic CGE modelers in building their own baselines.