Pareto principle

A social state is said to be Pareto-efficient when there is no feasible alternative to it in which at least one individual is better off while no individual is worse off. The Pareto principle tells us to move from Pareto-inefficient to Pareto-efficient states. Suppose a large basket of fruit is shared among a group in some way or another – one apple, two peaches, a dozen cherries each, for instance. If the fruit can be exchanged so that at least some people get more enjoyment from what they have, and no one gets less, the Pareto principle instructs us to do so; indeed, it instructs us to carry on exchanging until no more improvements of this kind are possible.