In Teruvia, the quantity of rice produced per year is currently just large enough to satisfy domestic demand. Teruvia' s total rice acreage will not be expanded in the foreseeable future, nor will rice yields per acre increase appreciably. Teruvia' s population, however, will be increasing significantly for years to come. Clearly, ttherefore, Teruvia will soon have to begin importing rice.
An assumption on which the argument depends is that there are no major crops other than rice for which domestic production and domestic demand are currently in balance in Teruvia.