摘要：American agriculture is inexorably concentrating into the hands of a small number of large conglomerates. Expanding farms pursuing scale economies would normally have to abide by a system of environmentalother laws that would, in theory, require farms to account for negative externalities. If those laws were observedenforced, they would help strike a balance between the greater profitabilitythe larger externalities of scaling up. But these laws are not widely observed nor rigorously enforced, which upsets this balancegives large-scale farms a cost advantage while insulating them from corresponding responsibilities.
