116. Pareto Optimality, noun. Any distribution of resources within a given economy such that it would be impossible to change the way resources are allocated in order to benefit any individual or group without simultaneously making another individual or group worse off. In game theory, Pareto optimality refers to any outcome in which no player can improve their situation without harming another player. To reach a Pareto optimal outcome is not necessarily the same thing as reaching the fairest, most desirable, or most moral solution to the problem at hand; it is only the case that one has achieved some quantifiable measure of efficiency. The term is also used in mathematics to describe a result in which the values of two or more interdependent variables have been optimized.


After the late 19th/early 20th-century Italian economist Vilfredo Pareto, who first described this type of outcome, + Latin optimum, “best.”


Let us say you and I prefer to be together, but you would rather ride the trains on sparking tracks and I would rather pick my way up mountainsides. Which choices leave each of us unable to take a step without doing mischief to the other’s happiness? Does joy result from equilibrium?