Pareto optimality

A state of affairs where it is not possible to improve the economic lot of some people without making others worse off; a mercantilist view. The implications of this view in welfare economics are that, once an economy has ceased to grow, it is impossible to increase the wealth of the poor without opposing the Pareto criterion; in other words, without making the rich worse off. This then becomes an argument for retaining the status quo, even if the distribution of income in society is very uneven. A Pareto improvement, however, occurs if resources can be better utilized so that one group's prosperity increases, but not at a cost to another's.