A Pigouvian tax (also spelled Pigovian tax) is a tax on a market activity that generates negative externalities, that is, costs incurred by third parties. It imposes costs corresponding with the externalities, internalizing those costs to improve Pareto efficiency. Ideally, the tax is set equal to the external marginal cost of the negative externalities, in order to correct an undesirable or inefficient market outcome (a market failure).
In the presence of negative externalities, parties who did not consent to the transaction or activity, and did not receive payment, nevertheless incur some of the costs, so the total cost is not covered by the private cost of the activity. In such a case, the market outcome is not efficient and may lead to a harmful excess of the activity. Examples of negative externalities are environmental pollution and increased public healthcare costs associated with tobacco and sugary drink consumption.
Conversely, in the presence of positive externalities, those who did not directly participate in the market activity, or contribute to the production, receive some benefit, and the market may under-produce. This suggests a Pigouvian subsidy to help consumers pay for socially beneficial products and encourage increased production to generate more positive societal benefits.
Examples are a subsidy for flu vaccines, for research and development, and for public goods such as education and national defense.Multiple sources:
Pigouvian taxes are named after the English economist Arthur Cecil Pigou (1877–1959), who developed the concept of economic externalities. William Baumol was instrumental in framing Pigou's work in modern economics in 1972.
Pigou's original argument In 1920, the British economist Arthur Cecil Pigou published The Economics of Welfare. In it, he argues that industrialists seek their own marginal private interest. When the marginal social interest diverges from the marginal private interest, the industrialist has no incentive to internalize the marginal social cost. Conversely, Pigou argues, if an industry produces a marginal social benefit, the individuals receiving the benefit have no incentive to pay for that service. Pigou refers to these situations as incidental uncharged disservices and incidental uncharged services, respectively.
Pigou provides numerous illustrations of incidental uncharged disservices. For example, if a contractor builds a factory in the middle of a crowded neighborhood, the factory causes these incidental uncharged disservices: higher congestion, loss of light, and a loss of health for the neighbors. He also references businesses that sell alcohol. The sale of alcohol necessitates higher costs in policemen and prisons, Pigou argues, because of the crime associated with alcohol. In other words, the net private product of alcohol businesses is peculiarly large relative to the net social product of the same business. He suggests that this is why most countries tax alcohol businesses.
The divergence between the marginal private interest and the marginal social interest produces two primary results. First, as already noted, the party receiving the social benefit does not pay for it, and the one creating the social harm does not pay for it. Second, when the marginal social cost exceeds the marginal private benefit, the cost-creator over-produces the product. Ultimately, because non-pecuniary externalities overestimate the social value, they are over-produced.
To deal with over-production, Pigou recommends a tax placed on the offending producer. If the government can accurately gauge the social cost, the tax could equalize the marginal private cost and the marginal social cost. In more specific terms, the producer would have to pay for the non-pecuniary externality that it created. This would effectively reduce the quantity of the product produced, moving the economy back to a healthy equilibrium.
Working of the Pigouvian tax
A tax shifts the marginal private cost curve up by the amount of the externality. If the tax is placed on the quantity of emissions from the factory, the producers have an incentive to reduce output to the socially optimum level. If the tax is placed on the percentage of emissions per unit of production, the factory has the incentive to change to cleaner processes or technology.
Taxing proxies
Taxing proxies for the negative externalities, such as taxing production as a proxy for emissions, has been argued to sometimes fail to deliver efficient market outcomes. Even less effective are lump-sum taxes on industry participation, such as licensing, especially when the number of firms can vary.
Pigouvian tax on measures of emissions themselves (or the relevant negative externalities) can create the long-run efficient market and social optimum.
Double-dividend hypothesis The double-dividend hypothesis proposes that a revenue-neutral substitution of environmental taxes for revenue-raising taxes might offer two benefits. The idea was first advanced by Tullock (1967) in a paper titled "Excess Benefit".Tullock, G. (1967), "Excess benefit", Water Resources Research, 3, 643–44. The first benefit (or dividend) is the benefit or welfare gain resulting from a better environment and less pollution (caused by a Pigouvian tax imposed on the producer), and the second dividend or benefit is a more efficient tax system due to a reduction in the distortions of the revenue-raising tax system, which also produces an improvement in welfare. This idea received scant attention until the early 1990s when the economics of climate change attracted attention to the topic of environmental taxes. The concept of "double dividend" became widely used following its introduction by David Pearce in 1991. Pearce noted that estimates of the marginal excess burden (marginal distortionary cost) of existing levels of taxation in the US economy are between 20 and 50 cents per dollar of revenue collected. Because the revenue from the carbon tax would be recycled (used to lower preexisting and distorting taxes), the policy would be revenue-neutral, and the secondary benefit from revenue recycling would justify an even higher carbon tax. It is generally accepted now that the magnitude of the "revenue-recycling" benefit is lower than the 20–50 cents per dollar of revenue, but there are differing views on whether the second effect is positive or negative. The line of argument suggesting that the second "benefit" is negative proposes a previously unrecognized "tax interaction effect" (Bovenberg and de Mooij 1994).Bovenberg, A.L. and R.A. de Mooij (1994), 'Environmental levies and distortionary taxation', Ameri¬can Economic Review, 94 (4), 1085–89.
In a 1997 paper, Don Fullerton and Gilbert E. Metcalf evaluated the double dividend hypothesis. They define the double-dividend hypothesis as the theory that environmental taxes can improve the environment and increase economic efficiency simultaneously. Either motivation can legitimately support a tax reform. The first dividend intuitively makes sense: decreasing pollutant emissions improves the environment. The improvement in economic efficiency results from a shift away from distorting taxes such as the income tax. Fullerton and Metcalf note that for every $1 extracted in taxes, a $1.35 burden falls on the economy. In a sense, the private sector must swallow a 35 cent excess burden for no particular reason. The second dividend aims to eliminate some of this excess burden.
Fullerton and Metcalf argue, the validity of the double-dividend theory cannot be established as a whole. This does not imply that the double dividend hypothesis is untenable but there is just more complication to that. An observer must evaluate each circumstance individually. Fullerton and Metcalf do provide guidelines for this analysis. Two questions help shape this analysis: what is the status quo? What are the specifics of the reform? The amount and nature of the current taxes, permits, and regulations greatly influence the results of the additional tax. Also, where the tax revenue goes greatly affects the success of the tax.
Secondly, Fullerton and Metcalf say the previous literature on Pigouvian taxes focused too heavily on the revenue dividend and too lightly on the environmental dividend of environmental taxes. Their predecessors naively value revenue too much, Fullerton and Metcalf argue, because they fail to recognize that all taxes impose costs on someone. These taxes could outweigh the environmental benefit. Thus, the government must use the Pigouvian tax revenue to lower another tax if it wants to minimize the economic damage of a tax.
Fullerton and Metcalf also mention that the effectiveness of any sort of Pigouvian tax depends on whether it supplements or replaces an existing pollution regulation. If the tax replaces a pollution regulation, it will most likely be environmentally neutral, even if it is revenue-positive. If it supplements the regulation, it may or may not be environmentally and revenue-neutral, depending on the effectiveness of the original regulation. The status quo substantially affects the outcome of a proposed tax.
Distortionary taxation A. Lans Bovenberg and Ruud A. Mooij argue that there is a first-best case scenario and a second-best case scenario in their article "Environmental Levies and Distortionary Taxation."Bovenberg, A. Lans and de Mooij, Ruud A. (1994). "Environmental Levies and Distortionary Taxation," The American Economic Review, 84(4): 1085–1089. In the first-best case, the government does not need to get revenue from distortionary taxes such as the income tax, and the Pigouvian tax can create the long-run social optimum. In the real world, second-best case, the status quo includes an income tax that distorts the labor supply. In this situation, Bovenberg and Mooij write that the best tax comes in below the level of the Pigouvian tax.
Bovenberg and Mooij establish that households consume a dirty good (D) and a clean good (C). If the government taxes D, it can use the earned revenue to lower the labor income tax. At the same time, the tax levied on the firm will increase the price of D. The lowered income tax and the higher consumer prices even each other out, stabilizing the real net wage. But because C's price has not changed and it can substitute for D, consumers will buy C instead of D. Suddenly the government's environmental tax base has eroded and its revenue with it. The government then cannot afford to keep the labor income tax down. Bovenberg and Mooij posit that the increase in the price of goods will outweigh the slight decrease in the income tax. Labor and leisure become more interchangeable the lower the real net wage (or after-tax wage) falls. With this decrease in the real net wage, more people leave the job market. Ultimately, labor bears the cost of all public goods.
Goulder, Parry, and Burtraw agree that the net social welfare after the implementation of a tax hinges on the preexisting tax rate. Don Fullerton agreed with this analysis in 1997 in his article "Environmental Levies and Distortionary Taxation: Comment".Fullerton, Don (1997). "Environmental Levies and Distortionary Taxation: Comment," The American Economic Review, 87(1): 245–251. He added that lowering the income tax and taxing the dirty good equates with raising the labor tax and subsidizing the clean product. These two policies create the same effects, Fullerton says.