Rothbard on the Myth of Social Efficiency
"[I]ndividual ends are bound to conflict, and therefore any additive concept of social efficiency is meaningless. . . . Efficiency . . . can only be meaningful relative to a given goal. But if ends clash, the opposing group will favor maximum inefficiency in pursuit of the disliked goal. Efficiency, therefore, can never serve as a utilitarian touchstone for law or for public policy. . . . [C]osts, as Austrians have pointed out for a century, are subjective to the individual, and therefore can neither be measured quantitatively nor, a fortiori, can they be added or compared among individuals. But if costs, like utilities, are subjective, nonadditive, and noncomparable, then of course any concept of social costs, including transaction costs, becomes meaningless." ("The Myth of Efficiency," in Time, Uncertainty, and Disequilibrium, Mario Rizzo, ed.)
As I argued in my post on "The So-Called Green Revolution," the most "efficient" agricultural techniques for a piece of land depend on who owns it and his goals in farming it. The techniques of large-scale commercial farming, with heavy mechanization and intensive use of chemicals and GMOs, are "more efficient" for those who happen to have huge tracts of land and heavily subsidized irrigation and other inputs, and are producing for export markets or the cities. For the peasant who farms a small tract of land and whose objective is to feed himself and his family as self-sufficiently as possible, the most efficient techniques will more likely involve careful stewardship of the soil and the use of drought-hardy locally improved varieties of seed. To say that the robbers make "more efficient" use of the land begs the question of whose ends should prevail: the robbers or the robbed?