The term was coined by Jacob Viner in "The Customs Union Issue" in 1950. In its literal meaning the term was however incomplete, as it failed to capture all welfare effects of discriminatory tariff liberalization, and it was not useful when it came to non-tariff barriers. Economists have however dealt with this incompleteness in two ways. Either they stretched the original meaning to cover all welfare effects, or they introduced new terms like trade expansion or internal versus external trade creation.