There are two sources of bias in the existing gravity equations used to assess the impact of non-reciprocal preferential trade policies (NRPTPs). The main inconsistency comes from the use of aggregate export flows at country level to analyse the effects of trade preferences which, by contrast,...

This paper reviews the empirical literature using a gravity model to assess the impact on trade of Preferential Trade Agreements (PTAs) and provides a critical analysis of the choices made to carry out the estimations. With respect to the effectiveness of PTAs, the main result that emerges from...