In economics, a trade-off refers to a situational decision that involves diminishing or losing one quality, quantity, or property of a set or design in return for gains in other aspects. A trade-off involves a sacrifice that must be made to obtain a certain product, service, or experience. The concept of a trade-off is often used to describe situations in everyday life, and in economics, it is expressed in terms of the opportunity cost of a particular choice, which is the loss of the most preferred alternative given up. The idea of trade-offs is one of the most basic principles in economics, that in order to have more of one thing, you have to accept having less of something else. Trade-offs are evaluated based upon their opportunity cost, which is the value of what is lost when choosing one thing over another. Theoretical description of trade-offs involves the Pareto front. At the macroeconomic level, trade-offs determine what a country produces for international trade.