Some libertarians cheer whenever there is any tax repeal. However, we need to distinguish taxes in form versus taxes in substance. Taxes in substance have no relation to a benefit or penalty attached to the payment. Taxes in form, but not in substance, pay funds to the government, but are tied to some benefit or compensation for damages.

It is standard economic theory that the best way to prevent pollution, as with other negative The effects, is to make the polluter, hence also the buyer of its products, pay the social cost of the pollution. The economist Arthur Cecil Pigou provided a thorough explanation in his 1920 book The Economics of Welfare. A tax on pollution has since then been called “Pigovian.”

One of the most discussed Pigovian taxes has been on the use of carbon-based fuels such as coal, natural gas, and oil. A “carbon tax” can be on the fuel inputs or on the emission outputs. The most effective Pigovian levy is on the emissions, as that provides an incentive to reduce pollution such as by capturing the carbon before it gets spewed out. If the polluter does not compensate society for dumping on the commons, then in effect it gets subsidized, as it sells its output at less than the total social cost of production.

Many countries have been confronting pollution with inefficient policies such as regulations, credits for offsetting pollution with purchases of forest lands, and permits that can be traded. Australia enacted what was called a “carbon tax” with the Clean Energy Act of 2011, implemented in July 2012. But this was not a Pigovian tax. The Act created a “carbon price mechanism,” a cap-and-trade emissions trading scheme that at first set a price per ton of emissions. This mandated price had the effect of a ‘carbon tax’. But after 2015, the mechanism would have transitioned to a trading scheme.

However, in 2013 the newly elected prime minister sought a repeal of the “carbon tax” emissions trading scheme. In 2014, parliament passed the repeal.

The opponents of emissions taxes claim that this increases costs to business and households. This is narrowly true, but policy should consider the total costs to society. The pollution imposes a social cost on Australia and the rest of the world. This is not a cost paid in explicit money, but costs in the form of illness, a less productive environment, and possible effects on the climate.

The opponents of emission levies overlook that the absence of compensation for the pollution costs is in effect a subsidy to the polluters and their customers. A pollution charge is not a tax in substance, but rather the prevention of this subsidy, and compensation for dumping toxic materials on other people’s property.

The repeal did not provide a replacement, and this creates uncertainty for business about any future anti-pollution policy. This policy uncertainty reduces investment and growth.

The best way to implement a pollution tax is as a replacement of other taxes. Taxes in income, sales, and value added impose the excess burden of higher costs and less output and employment. If politicians are concerned with tax costs, why are they not repealing these taxes? When a pollution tax replaces such market-hampering taxes, the total costs paid by consumers does not increase, but rather shifts in favor of less- polluting products.

Actually, the revenue obtained from Australia’s brief carbon tax was used to compensate taxpayers and affected companies. But the most effective policy would have been to have an explicit tax on pollution instead of a trading scheme, and to lower other tax rates, along with a transitional compensation to those with net losses.

Some opponents claim that Pigovian charges would be good if applied globally, but in a single country, would put its industries at a disadvantage. But that would not happen with a “green tax shift,” the replacement of inefficient taxes with a “green tax” on pollution. A green tax shift would reduce the environmental cost of pollution while not increasing the total tax costs for the country’s economy.