Externalities in the context of "Deregulation"

A Pigouvian tax (also spelled Pigovian tax) is a tax on a market activity which is generating 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.

An environmental tax, ecotax (short for ecological taxation), or green tax is a tax levied on activities which are considered to be harmful to the environment and is intended to promote environmentally friendly alternatives via economic incentives. One notable example is a carbon tax. Such a policy can complement or avert the need for regulatory (command and control) approaches. Often, an ecotax policy proposal may attempt to maintain overall tax revenue by proportionately reducing other taxes (e.g. taxes on wages and income or property taxes); such proposals are known as a green tax shift towards ecological taxation. Ecotaxes address the failure of free markets to consider environmental impacts.

Ecotaxes are examples of Pigouvian taxes, which are taxes on goods whose production or consumption creates external costs or externalities. An example might be philosopher Thomas Pogge's proposed Global Resources Dividend.

In neoclassical economics, market failure is a situation in which the allocation of goods and services by a free market is not Pareto efficient, often leading to a net loss of economic value. The first known use of the term by economists was in 1958, but the concept has been traced back to the Victorian writers John Stuart Mill and Henry Sidgwick.Market failures are often associated with public goods, time-inconsistent preferences, information asymmetries, failures of competition, principal–agent problems, externalities, unequal bargaining power, behavioral irrationality (in behavioral economics), and macro-economic failures (such as unemployment and inflation).

The neoclassical school attributes market failures to the interference of self-regulatory organizations, governments or supra-national institutions in a particular market, although this view is criticized by heterodox economists. Economists, especially microeconomists, are often concerned with the causes of market failure and possible means of correction. Such analysis plays an important role in many types of public policy decisions and studies.

Groundwater-related subsidence is the subsidence (or the sinking) of land resulting from unsustainable groundwater extraction. It is a growing problem in the developing world as cities increase in population and water use, without adequate pumping regulation and enforcement. One estimate has 80% of serious U.S. land subsidence problems associated with the excessive extraction of groundwater.

Groundwater can be considered one of the last free resources, as anyone who can afford to drill can usually draw up merely according to their ability to pump (depending on local regulations). However, pumping-induced draw down causes a depression of the groundwater surface around the production well. This can ultimately affect a large region by making it more difficult and expensive to pump the deeper water. Thus, the extraction of groundwater becomes a tragedy of the commons, with resulting economic externalities.

Congestion pricing or congestion charges is a system of surcharging users of public goods that are subject to congestion through excess demand, such as through higher peak charges for use of bus services, electricity, metros, railways, telephones, and road pricing to reduce traffic congestion; airlines and shipping companies may be charged higher fees for slots at airports and through canals at busy times. This pricing strategy regulates demand, making it possible to manage congestion without increasing supply.

According to the economic theory behind congestion pricing, the objective of this policy is to use the price mechanism to cover the social cost of an activity where users otherwise do not pay for the negative externalities they create (such as driving in a congested area during peak demand). By setting a price on an over-consumed product, congestion pricing encourages the redistribution of the demand in space or in time, leading to more efficient outcomes.

In neoclassical economics, a market distortion is any event in which a market reaches a market clearing price for an item that is substantially different from the price that a market would achieve while operating under conditions of perfect competition and state enforcement of legal contracts and the ownership of private property. In other words, a distortion is "any departure from the ideal of perfect competition that therefore interferes with economic agents maximizing social welfare when they maximize their own". A proportional wage-income tax, for instance, is distortionary, whereas a lump-sum tax is not. In a competitive equilibrium, a proportional wage income tax discourages work.

In perfect competition with no externalities, there is zero distortion at market equilibrium of supply and demand where price equals marginal cost for each firm and product. More generally, a measure of distortion is the deviation between the market price of a good and its marginal social cost, that is, the difference between the marginal rate of substitution in consumption and the marginal rate of transformation in production. Such a deviation may result from government regulation, monopoly tariffs and import quotas, which in theory may give rise to rent seeking. Other sources of distortions are uncorrected externalities, different tax rates on goods or income, inflation, and incomplete information. Each of these may lead to a net loss in social surplus. Market distortions are events, decisions, or interventions taken by governments, companies, or other agents, often in order to influence the market. They are often the response on market failures, i.e., circumstances that prevent perfect competition and achieving an optimal equilibrium in the market.