In economics, the concept of “optimal” is often used: optimal taxation, optimal pollution, optimal consumption, etc. Optimal, in an economic sense, just means marginal benefit equals marginal cost. For individual actors, such a definition and usage makes sense. However, problems arise when trying to generalize optimality over collective units.
With optimality, it is important to remember a key characteristic about benefits and costs: they are subjective. All value, whether a benefit or a cost, is subjective. Therefore, an individual can optimize his behavior by aligning his subjective marginal benefits and subjective marginal costs. But this is not true with collective action. When analyzing collective action, the point of view of the analyzing person comes into play. Collective agencies cannot have subjective feelings about things, they cannot optimize; the one who does the analysis optimizes based on his/her subjective values.
Therefore, it doesn’t make sense to talk about the optimization of collective units in the same way it does to talk about the optimization of individual units. Concepts like “optimal tariffs,” “optimal taxation,” etc., lose their meaning when we start considering subjective costs. It comes down very heavily to the subjectivity of the person who is doing the calculating, what he/she believes the costs/benefits are. When that individual is responsible (ie, they pay the cost if they are incorrect) for the results of their actions (eg, the owner of a firm), then such subjectivity is not an issue; they are properly incentivized to make sure their subjective understanding aligns with their collective goal. When the person is not responsible (eg, government agents), then such optimization becomes…problematic.