Traditionally, food security is defined in terms of either food self-sufficiency or food self-reliance. The former requires production of various food items in the quantities consumed domestically while the latter requires domestic availability. Based on this distinction, self-sufficiency rules out imports as a source of supply while self-reliance admits them. In modern times, given much larger worldwide capacity to produce food than consume it, few restrictions on the exports of food items in countries with the excess capacity, and the availability of the means of transportation that allow their rapid movement internationally, self-sufficiency makes little economic sense. Instead, what countries need is sufficient capacity to generate foreign exchange by specializing in goods of their comparative advantage and import the excess of quantities consumed over those produced.
