摘要：Impact assessments of policy interventions on agricultural commodity prices are carried out by international
organizations using nationwide measures which overlook the effects of spatial heterogeneity in incomplete markets.
We introduce a multi-step methodology to build spatially-disaggregated nominal rates of protection in a data-scarce
environment and test it along the maize value chain in Uganda. Results confirm that the spatial dispersion of farmers
plays a key role in determining heterogeneity in nominal rates of protection. This finding has far-reaching policy
implications: i) the assumption of a nationally-representative market pathway is unrealistic; ii) pan-national
interventions may exacerbate, rather than reduce, price distortions.
