Where more than one policy is available, the decision maker must also decide which policy to select. The criteria for selecting the policy are efficiency, neutrality, and equity. Efficiency The least-cost policy. Economists are concerned with the conservation of scarce resources. Neutrality The least-distorting policy.
Economists are also concerned with the allocation of resources.
If policy distorts individual behavior and forces people to do things they would not do without the policy, then resources are reallocated. Unless society's goal is specifically to rearrange its resources, policies which distort are inefficient. The fairest policy. Economists are generally not concerned with subjective outcomes, like fairness. What is fair to one person may not be fair to another.