by MH Lubinga, AA Ogundeji, H Jordaan and AJ Verschoor, this paper evaluates the impact of the Generalized System of Preferences (GSP) scheme on horticultural exports from Kenya, Tanzania, and Uganda to the European Union (EU). The preference margin, computed as the difference between trade weighted Most Favoured Nation’s rate and the ad valorem equivalents(, is used as a proxy for the GSP scheme. The zero inflated Poisson estimator is used to control for.