Many studies use tariffs to measure changes in trade policy. This paper shows that standard sources for tariffs suffer … from substantial measurement error due to misreporting and the resulting false imputation: Countries fail to report tariffs … every year and missing data are more prevalent for preferential than for most favored nation (MFN) tariffs. WITS, the main …

to the elimination of tariffs and cuts in non-tariff measures by 25%, is in the range of 1% to 4% of initial consumption …