Its creator supposed that utilitarian addition of welfare across individuals is meaningless, and that the only useful aggregate measures of welfare must be ordinal.  
Although its criteria are generally thought to be positive rather than normative, they are often used as normative principles for justifying particular changes or refusals to make changes.  Its creator supposed that utilitarian addition of welfare across individuals is meaningless, and that the only useful aggregate measures of welfare must be ordinal.  Defined as the state of affairs in which no one can be made better off without making someone worse off, FTP, identify this optimality named after an Italian economist.
Although its criteria are generally thought to be positive rather than normative, they are often used as normative principles for justifying particular changes or refusals to make changes.  
Pareto efficiency or optimality