The income terms of trade of a country is defined by Dorrance as :

Income terms of trade measure the import-purchasing capacity of exports: (Pₓ/Pₘ)Qₓ. Multiplying export price by export quantity gives export revenue; dividing by import price converts it into import volume. (Pₓ)(Pₘ)(Qₓ) multiplies instead of dividing by import price. (Pₘ/Pₓ)×100 is inverse net barter terms, and (Pₘ/Pₓ)Qₓ also reverses the price ratio.