Estimating the Potential Output and Output Gap of Ghana

This paper focuses on the estimation of the potential output of Ghana. Potential output or its derivative the output gap are not observable. However, “potential output” is a powerful conceptual tool that guides analysts and policymakers in gauging whether the current observed economic activity is sustainable and how much of it is greater than or less than potential. Based on Ghanaian GDP annual data from 1960 – 2017, the paper estimates potential output and output gaps using the following methodology: linear time trends, Hodrick-Prescott (HP) filter trends, multivariate HP filter trends, and a production function model. The results show that estimates of the potential output and output gaps are model-dependent as estimates vary from one methodology to the other. The paper recommends that policymakers should not mechanically choose a model to estimate output gap. For the avoidance of costly policy mistakes, the choice of the model should be complemented with sound judgement based on a set of pertinent economic information.