A second-best evaluation of eight policy instruments to reduce carbon emissions

This paper uses a numerical general equilibrium model to compare the costs of alternative policies for reducing carbon emissions in a second-best setting with a distortionary tax on labor. We examine a carbon tax, two energy taxes, and both narrow-based and broad-based emissions permits and performance standards. The presence of pre-existing tax distortions raises the costs of all these policies, and can affect their relative cost rankings. In fact, the superiority of emissions taxes and emissions permits over other instruments can hinge on whether these policies generate revenues that are used to reduce other distortionary taxes.     

Prices vs. Quantities with fiscal cushioning

Enforcement of international environmental quantity regulations (e.g. tradable pollution permits) is often expected to be stricter than that of price regulations (e.g. emission taxes). While both instruments provide opportunities for misrepresenting actual pollution, enforcement of international price-based instruments is additionally hampered by potential fiscal cushioning, i.e. an adjustment of domestic fiscal policies offsetting the tax incentive to reduce emission reductions. The present paper extends the formal debate on Prices vs. Quantities by including the risk of fiscal cushioning. We find the level of the marginal benefit curve and the variance of costs become key elements for instrument choice and can render quantity regulations strictly preferable. Remarkably, in the latter case, the slopes of the marginal curves do not affect optimal instrument choice. Numerical calculations, using data taken from the international climate policy context, support the potential dominance of quantity regulations found in our formal analysis.     

Technology Diffusion with Market Power in the Upstream Industry

This paper compares taxes and tradable permits when used to regulate a competitive and polluting downstream industry that can purchase an abatement technology from a monopolistic upstream industry. Second-best policies are derived for the full range of the abatement technology’s emission intensities and marginal abatement costs. The second-best permit quantity can be both above or below the socially optimal emission level. Explicit consideration of the output market provides further insights on how market power distorts the allocation in the downstream industry. The ranking between permits and taxes is ambiguous in general, but taxes weakly dominate permits if full diffusion is socially optimal. In addition, it is analysed how a cap on the permit price affects the diffusion of an abatement technology.     

Second-best theory and the use of multiple policy instruments

In many cases policy makers employ multiple instruments to address a single environmental problem, but much of the economics literature on instrument choice focuses on comparing properties of single policy instruments. We argue that under a fairly broad set of circumstances the use of multiple policy instruments can be justified as optimal in a second-best world. We examine two broad categories of second-best policy making: cases with multiple market failures only some of which can be corrected at any one time; and cases with exogenous (often political) constraints that cannot be removed. The fact that the use of multiple policy instruments can be justified economically in these two cases does not imply, however, that all multiple instruments employed in actual practice are economically justified.     

Involuntary Unemployment and Environmental Policy: The Double Dividend Hypothesis

An environmental tax reform might bring about gains over and above improved environmental quality. In particular, if tax revenues from environmental taxes are used to reduce the tax on wage income, positive employment effects can result in second-best economies. An efficiency wage model is used to analyze the impact of an ecological tax reform on involuntary unemployment. The government controls emissions by selling emission permits. Employment of labor and wages are determined endogenously. Conditions are identified under which an environmental tax reform reduces unemployment and increases welfare.     

Optimal tax rules and public sector efficiency with an externality in an overlapping generations model

This paper examines optimal tax rules and public sector efficiency, integrating them in a second-best world with pollution by using an overlapping generations model. The second-best world is characterized by the comparative statics of green preferences. The main results obtained are as follows. First, the marginal cost of public funds may be reduced by the externalities, regardless of the choice of taxes. Second, optimal environmental and non-environmental tax rules are additively and directly affected by the dynamic efficiency of capital accumulation per unit labour (DECAL), and indirectly by it, through the efficiency of the public sector. Environmental taxes going beyond Pigovian ones may be welfare-improving if the DECAL is improved by the environmental tax. Even optimal non-environmental tax rules should additively and directly counter the dynamics of pollution to consider the income effects of the optimal tax system for the future. Third, the “additivity property,” or the “principle of targeting,” does not hold even in the absence of incentive compatibility constraints. The essential reasons for this are clarified as follows: distortions that should be countered by taxes; that is, the income effects of the optimal tax system and the DECAL in this model, break the equality between optimal environmental taxes and the externalities measured by governments. Finally, growing environmental concerns may, in fact, increase pollution. The inverse relationship between environmental and labour income taxes may not hold.     

Does a Recession Call for Less Stringent Environmental Policy? A Partial-Equilibrium Second-Best Analysis

This paper analyses second-best optimal environmental policy responses to real and financial shocks in a two-period partial equilibrium model with heterogeneous firms, an environmental externality, and credit constraints. We show that, to alleviate credit constraints and encourage investment, the second-best optimal emission tax falls short of marginal emission damages. The optimal response to shocks depends on how the shock affects the size of the environmental and credit market failures and the effectiveness of the tax in alleviating these market failures. Under mildly restrictive assumptions on functional forms, the optimal response to a (persistent) negative productivity shock or a tightening of credit is to reduce the emission tax. Our results are informative for how climate change policy should optimally change with the business cycle.     

On the efficiency of environmental instruments in a spatial economy

This paper develops an efficiency criterion to evaluate environmental policy instruments in a spatial economy. We call an environmental policy regime at the regional level efficient if it guarantees not only an efficient distribution of emission permits within a region, but also an efficient locational pattern of mobile firms across the regions of a federation. Using marketable pollution rights or emission taxes, efficiency in this broad sense can only be achieved if revenues of regional environmental agencies are not transferred to regional firms. Direct controls neither support an efficient allocation of emission rights within a region nor locational efficiency of firms.     

Externalities and optimal taxation

This paper reexamines the optimal tax design problem (income and commodities) in the presence of externalities. The nature of the second–best, and the choice of the tax instruments, are motivated by the informational structure in the economy. The main results are: (i) environmental levies (linear or nonlinear) differ in formula from Pigouvian taxes by the expressions for the optimal tax on private goods; (ii) externalities do not affect commodity tax formulas (linear and nonlinear) for private goods; (iii) externalities do not affect the income tax structure if commodity taxes are nonlinear and affect it if commodity taxes are linear; and (iv) a general income tax plus strictly Pigouvian taxes are sufficient for efficient taxation if individuals of different types have identical marginal rates of substitution (at any given consumption bundle).     

Using Non Market Valuation to Inform the Choice Between Permits and Fees in Environmental Regulation

The purpose of this short note is to open an exploration regarding the use of non market valuation to help guide the selection of economically efficient pollution control instruments. As long as non market valuation techniques can correctly estimate the slope of the marginal benefit of abatement curve, this information along with engineering cost estimates of the unit costs or slope of the marginal abatement cost will provide useful information to policy makers in choosing between fees and permits. An illustrative review of the literature suggests that both stated and revealed preference methods have estimated slopes of marginal benefit functions for reducing several pollutants. To investigate the efficiency of permits versus fees, an illustrative review of corresponding marginal abatement costs is also made. For air pollutants affecting visibility, the slope of the marginal benefit curve is far greater than the slope of the marginal abatement costs, suggesting permits as the efficient instrument. For nitrates in groundwater used for drinking, the marginal benefit curve is flatter than the rather steep marginal abatement cost, suggesting fees/taxes would be a more efficient economic instrument. We hope this note stimulates more emphasis in non market valuation on estimating the slope of the marginal benefit function to enhance environmental economists ability to make policy recommendations regarding the choice of pollution instruments for specific pollutants.      

Weitzman Revisited: Emission Standards Versus Taxes with Uncertain Abatement Costs and Market Power of Polluting Firms

Studies dealing with the optimal choice of pollution control instruments under uncertainty have invariably taken it for granted that regulated firms face perfectly competitive markets. By introducing the product market into the stochastic framework of Weitzman (Rev Econ Stud 41:477–491, 1974), this paper shows for the case of a polluting symmetric Cournot oligopoly that Weitzman’s policy rule for choosing emission standards versus taxes with uncertain abatement costs is biased in the presence of market power. Since the oligopolists take into account their influence on the market price, their total abatement effort, including the restriction of output, is less vulnerable to miscalculations of the tax rate compared to price-taking firms. Consequently, the comparative advantage of instruments is shifted in favour of taxes. In a further step, the provided policy recommendations are generalised by abolishing the assumption that firms are symmetric.     

Prices versus Quantities in a Second-Best Setting

The choice between taxes and tradable permits has been independently analysed by two distinct research traditions. The first proceeds from Weitzman's partial equilibrium stochastic model and concludes that a tax should be preferred if the marginal abatement cost curve is steeper than the marginal environmental benefit curve. The second utilises deterministic general equilibrium models with pre-existing distortionary taxes. It concludes that non-revenue-raising instruments (e.g., grandfathered tradable permits) are costlier than revenue-raising ones (e.g., a tax on every unit of pollution or auctioned permits). To build a bridge between these two traditions, we introduce in Weitzman's model a positive cost of public funds due to pre-existing distortionary taxes. The tax admits a greater comparative advantage over the permits, as compared to Weitzman's classical result. Then, we assume that the regulated industry blocks any proposal that poses it too high an expected burden. This may require a transfer to firms, in the form of freely-allocated permits or lump-sum tax rebate. It turns out that if this acceptability constraint is binding, then the comparative advantage of taxes over permits is still reinforced. Quantitatively, even if the marginal benefit function is 50% more steeply sloped than the marginal cost function, the price instrument should be preferred. We also compare the expected net benefit of these two instruments to a contingent instrument which leads to the ex post optimum. The superiority of the contingent instrument over the quantity one is higher than in first-best.     

An open economy model of the effects of unilateral environmental policy by a large developing country

In this paper, we pose the following question. Why is it that despite the universal recognition of the need for global environmental protection, developing countries have been lax in instituting stringent environmental regulations? Addressing this question from an economic standpoint, we show that there are plausible theoretical circumstances in which a large developing country can be worse off if it chooses to implement environmental policy in an uncoordinated fashion. The empirical dimension of this question is stressed and the key parameters – such as elasticities and marginal propensities to consume – which are germane to any policy discussion regarding this issue are identified. Second, we study – once again from the perspective of a large developing country – the possibility of using the domestic tax structure optimally to attain environmental policy objectives in a second-best environment. This scenario involves taxing pollution indirectly, by using product taxes. Finally, keeping the empirical dimension of the question in mind, we show how to compute optimal externality correcting taxes. These taxes are primarily a function of different kinds of elasticities.     

Optimal Taxation for Polluting Oligopolists with Endogenous Market Structure

This paper examines the optimal output taxes for polluting oligopolists under endogenous market structure, in the presence of external costs that vary exogenously with aggregate output. For general functional forms, we show that (i) the equilibrium number of firms in an industry may differ from the socially optimal number of firms and (ii) the second-best optimal taxes under imperfect competition could be less than, equal to, or greater than marginal external damages depending upon the curvature of market demand.     

Managing Permit Markets to Stabilize Prices

The political economy of environmental policy favors the use of quantity-based instruments over price-based instruments (e.g., tradable permits over green taxes), at least in the United States. With cost uncertainty, however, there are clear efficiency advantages to prices in cases where the marginal damages of emissions are relatively flat, such as with greenhouse gases. The question arises, therefore, of whether one can design flexible quantity policies that mimic the behavior of price policies, namely stable permit prices and abatement costs. We explore a number of “quantity-plus” policies that replicate the behavior of a price policy through rules that adjust the effective permit cap for unexpectedly low or high costs. They do so without necessitating any monetary exchanges between the government and the regulated firms, which can be a significant political barrier to the use of price instruments.     

The Welfare Effects of Environmental Taxation

Recent literature has investigated whether the welfare gains from environmental taxation are larger or smaller in a second-best setting than in a first-best setting. This question has mainly been addressed indirectly, by asking whether the second-best optimal environmental tax is higher or lower than the first-best Pigouvian rate. Even this indirect question has itself been approached indirectly, comparing the second-best optimal environmental tax to a proxy for its first-best value, marginal social damage (MSD). On closer examination, however, MSD becomes ambiguously defined and variable in a second-best setting making it an unreliable proxy for the Pigouvian rate. Given these observations, the current analysis reevaluates these welfare questions and finds that when compared directly to its first-best value, the second-best optimal environmental tax generally rises with increased revenue requirements. Even in cases where the second-best environmental tax is lower than its first-best value, the welfare gains may be greater than in a first-best setting. These results suggest that the marginal fiscal benefit (revenue recycling effect) exceeds the marginal fiscal cost (tax base effect) over a range of environmental tax rates that, for benchmark models, extends above the first-best Pigouvian rate. These findings reinforce the intuition that environmental policy complements rather than competes with the provision of other public goods.     

Tax Competition in Vertically Differentiated Markets with Environmentally Conscious Consumers

This paper analyses the effects of tax competition on environmental product quality, pollution and welfare in a two-country, vertically differentiated, international duopoly, in which consumers are environmentally conscious. The firm in each country chooses first the environmental quality of its product (which reflects the emissions generated in the production process) and then the price. In equilibrium one country will be more polluted than the other because firms choose different levels of environmental quality of their products. We find that a country’s optimal commodity tax is higher if the domestic firm is the more polluting supplier. Furthermore, non-cooperative commodity tax rates are inefficiently high in equilibrium. This is because, in this framework with environmentally aware consumers, commodity taxes affect the choice of firms regarding their emissions. Therefore, a domestic tax reduction not only raises the profits of the foreign firm but also lowers its emission levels, resulting in higher welfare for the other country. We also analyse the optimal cooperative and non-cooperative commodity and emission taxes with border tax adjustments. With these two policy instruments available, commodity taxes are higher.     

Second-Best Pollution Taxes: an Analytical Framework and Some New Results

This paper compares the second-best optimal tax on polluting consumption goods with the Pigovian tax, which would internalize marginal environmental damage at a second-best optimum. It is shown that the relationship between the optimal tax on polluting consumption and the Pigovian tax is determined by the substitutability between labour and polluting consumption or clean and polluting consumption, depending on whether a wage tax system or a commodity tax system is being considered. The key factor determining the relationship between the two taxes is gross substitutability between the two taxed goods. As long as there is gross substitutability, the optimal dirt tax exceeds the Pigovian tax. The opposite can occur if and only if the two goods are gross complements.     

Environmental Taxation and Strategic Commitment in Duopoly Models

In this paper, we address the issue of optimalenvironmental taxation under imperfect competition.The problem is analysed for three different types ofduopoly models, the Cournot open and closed loopmodels, and the Stackelberg model. We explicitlyanalyse the role of strategic behaviour. Each firm hasto make a choice of output level and of the level ofa strategic variable. The choice of this strategicvariable affects both marginal cost and emissions. Wecompare the properties of these three duopoly models,and derive and compare optimal environmental taxes. Weshow that whether the optimal tax is lower or higherthan marginal environmental costs depends on theinformation transmission and the effect of thestrategic variable on marginal costs. In addition, thedifferences in market shares, and the influence of thetax on the cost structure play important roles, indetermining optimal emission taxes.     

Climate Policy,Learning, and Technology Adoption in Small Countries

A significant reduction in global greenhouse gas emissions requires international cooperation in emission abatement as well as individual countries’ investment in the adoption of abatement technology. The existing literature on climate policy pays insufficient attention to small countries, which account for a substantial proportion of global emission. In this study, we investigate how climate policy and learning about climate damage affect investment in abatement technology in small countries. We consider three alternative climate policy instruments: emission standards, harmonized taxes and auctioned permits. We say that learning is feasible if an international environmental agreement (IEA) is formed after the resolution of uncertainty about climate damage. We find that, either with learning and quadratic abatement costs or without learning, harmonized taxes outperform emission standards and auctioned permits in terms of investment efficiency. Without learning, a large cost of nonparticipation (that a country incurs) in the IEA can be beneficial to the country. Whether learning improves investment efficiency depends on the size of this nonparticipation cost.