Nrp and erp are constructed and compared with estimterminants of trade prates from previous studies to illustrate the evolution of protection in thailand over the past three decades. There has been no systematic analysis of the determinants of trade protection in thailand. previous studies for thailand are limited to estimating erp. A systematic analysis of protection variation across industries has not been attempted. As thailand has pursued a cascading tariff structure over the past four decades, the level of protection has varied considerably across industries.