In the most widely used regulatory approach to environmental pollution, a government agency tells a polluting agent how much pollution it can emit or requires the agent to use a particular production method aimed at reducing emissions. This method, in which the government agency tells a firm or individual how much or by what method emissions must be adjusted, is called the command-and-control-approach.
Economists are generally critical of the command-and-control approach for two reasons. First, it achieves a given level of emissions reduction at a higher cost than what would be required to achieve that amount of reduction if market incentives (discussed below) were implemented. Second, it gives polluters no incentive to explore technological and other changes that might reduce the demand for emissions.
Suppose two firms, A and B, each dump 500 tons of a certain pollutant per month and that there is no fee imposed (that is, the price for their emissions equals zero). Total emissions for the two firms thus equal 1,000 tons per month. The pollution control authority decides to cut this in half and orders each firm to reduce its emissions to 250 tons per month, for a total reduction of 500 tons. This is a command-and-control regulation because it specifies the amount of reduction each firm must make. Although it may seem fair to require equal reductions by the two firms, this approach is likely to generate excessive costs.
Suppose that Firm A is quite old and that the reduction in emissions to 250 tons per period would be extremely costly. Suppose that removing the 251st ton costs this firm $1,000 per month. Put another way, the marginal benefit to Firm A of emitting the 251st ton would be $1,000.
Suppose Firm B, a much newer firm, already has some pollution-control equipment in place. Reducing its emissions to 250 tons imposes a cost, but a much lower cost than to Firm A. Indeed, suppose Firm B could reduce its emissions to 249 tons at an additional cost of $100; the marginal benefit to Firm B of emitting the 249th ton is $100.
If two firms have different marginal benefits of emissions, the allocation of resources is inefficient. The same level of emissions could be achieved at a lower cost. Suppose, for example, Firm A is permitted to increase its emissions to 251 tons while Firm B reduces emissions to 249. Firm A saves $1,000, while the cost to Firm B is just $100. Society achieves a net gain of $900, and the level of emissions remains at 500 tons per month.
As long as Firm A’s marginal benefit of emissions exceeds Firm B’s, a saving is realized by shifting emissions from B to A. At the point at which their marginal benefits are equal, no further reduction in the cost of achieving a given level of emissions is possible, and the allocation of emissions is efficient. When a given reduction in emissions is achieved so that the marginal benefit of an additional unit of emissions is the same for all polluters, it is a least-cost reduction in emissions. A command-and-control approach is unlikely to achieve a least-cost reduction in emissions.
The inefficiency of command-and-control regulation is important for two reasons. First, of course, it wastes scarce resources. If the same level of air or water quality could be achieved at a far lower cost, then surely it makes sense to use the cheaper method. Perhaps even more significant, reliance on command-and-control regulation makes environmental quality far more expensive than it needs to be—and that is likely to result in an unwillingness to achieve the improvements that would be economically efficient.
There is a further difficulty with the command-and-control approach. Once firms A and B have been told to reduce their emissions to 250 tons per period, neither firm has an incentive to try to do better. Neither firm will engage in research seeking to reduce its emissions below 250 tons.
Another way to see the difficulty with command-and-control approaches to pollution control is to imagine that a similar method were in use for other resource allocation problems. Suppose, for example, that labor were allocated according to a commandand-control mechanism. Rather than leaving labor allocation to the marketplace, suppose that firms were simply told how much labor to use. Such a system would clearly be unworkable.
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