Expanding the household coverage of global simulation models: an application to Ghana

Computable general equilibrium (CGE) models, with their depiction of the whole economy, are well placed to capture the impact of economic shocks and policies on household food and nutrition security. However, many of the global models available include only a single representative household which conceals the impact on the most vulnerable households. This paper presents an alternative method for creating the data for extending the coverage of global CGE models to include different household types, based on the theory and structure of the MyGTAP model (Walmsley & Minor, 2013). The method allows the user to make country-specific choices about the way that national household data are integrated with the existing GTAP database. We make use of the household data processing work already embedded in national Social Accounting Matrices to disaggregate the single household in the GTAP database commonly used in global CGE models. We believe this method is quicker than processing the household survey data from scratch and retains the household detail available in the national Social Accounting Matrices. We illustrate the method with an application for Ghana in which multiple household types are added to the MAGNET CGE model using a household module containing the MyGTAP model code. The addition of multiple household types adds a range of food and nutrition security indicators which can be used in combination with all other MAGNET modules including those covering biofuels and nutrition, to identify impacts vary