1. Any argument for protection that can be countered by pointing to a different and less distortionary policy that would achieve the same desired result at lower economic cost. 2. An argument for protection to partially correct an existing distortion in the economy when the first-best policy for that purpose is not available. For example, if domestic production generates a positive externality and a production subsidy to internalize it is not available, then a tariff may be second-best optimal.