Revisiting tax effort in emerging markets

Insufficient tax revenues has been one of the most pervasive restrictions on investment in the social and economic infrastructure needed to close the development gaps in emerging markets (EM). To assess the potential for increasing tax collection, the literature has emphasized the concept of tax capacity and tax effort. Conceptually, tax effort is modeled as an inefficiency term with both time-varying and time-invariant components. These are commonly estimated through OLS or stochastic frontier analysis techniques. However, these strategies provide only point estimates and are limited in their ability to break down tax effort into time-varying and time-invariant components. We estimate tax effort for a balanced panel of 108 countries for which data were available from 2002 to 2017, using a Bayesian strategy that allows us to calculate the invariant inefficiency as an upper bound for a country’s tax effort. We also show that the GTRE model from Tsionas and Kumbhakar (2014) allows for more precise estimates, providing powerful tools for more informed fiscal planning.