This is not addressing my question at all. Efficiency can be understood as maximizing output for a given input (vernacular definition in use here). The moralit

This is not addressing my question at all. Efficiency can be understood as maximizing output for a given input (vernacular definition in use here). The morality of slavery is a red herring. We will ignore the research that suggests there was actually an efficiency cost to utilizing slavery over voluntary paid labor, because that is also irrelevant to the question. The question is whether forcing costs to be higher is an efficiency gain - it is not. We can now consider economic efficiency. One common measure is Pareto efficiency, which any change to the minimum wage cannot be in isolation, as one of the criteria is that no one be made worse off. The existence of a minimum wage also implies the existence of a Pareto optimal point. Another common measure of efficiency is Kaldor-Hicks efficiency, which basically takes the Pareto efficient criteria and modifies them such that there is a hypothetical compensation such that those being made better off could compensate those being made worse off to the point where all are made better off as a result. Essentially positive net utility change from some intervention. Note that the compensation is purely hypothetical, not necessarily monetary, and consequently unmeasurable. Kaldor-Hicks is the efficiency model wherein forcing a higher price can increase efficiency. You've not addressed this with a vague appeal to morality. Note: I am not trying to be hypercritical, only very clear in my statement.