The indicators for economic productivity in the US began to lag in the early 1970s just when major new environmental laws came into effect. It has been argued that this layer of industrial regulation triggered the productivity slowdown. This report counters this argument by showing how the conventional measure of productivity growth misrepresents the industrial process by taking into account only pollution abatement costs and ignoring pollution damages averted by regulations. The authors propose an alternative, unbiased productivity measure and demonstrate how this methodological change recasts the productivity pictures in case studies of the electric power, pulp and paper and agricultural sectors.