Commodity taxes and welfare under endogenous market conduct

We consider consumption taxes in a model of endogenous Cournot versus Bertrand competition. It is argued that when the choice of unit versus ad valorem taxes affects longer-term decisions beyond the customary price or quantity decisions, the mix of the two taxes co-determines market conduct. This gives ad valorem taxes an anti-competitive effect that harms ad valorem taxes’ efficiency in comparison with unit taxes. We show that a mix of the taxes—or a unit tax alone if we compare one or the other of the taxes—is sometimes welfare superior on account of consumer-price and tax revenue effects. A practical implication of our findings is that pass-through rates are only sometimes useful guides for policy. In fact, we show when the proper response to demand for higher revenue is a higher unit tax rate and a lower ad valorem tax rate.     

How should commodities be taxed?: Market structure,product heterogeneity and the optimal structure of commodity taxes

This paper is concerned with the form in which commodity taxes are best imposed, and particularly with the appropriate balance between specific and ad valorem components. This neglected issue is of policy importance in relation to the harmonization of tax structures within the EEC, and of theoretical interest as a point of contact between optimal tax theory and models of non-price competition. The roles of the two taxes as purely corrective devices under a variety of market forms are established and discussed. The analysis suggests that heavily taxed commodities should normally be subject to high specific rather than high ad valorem taxes.     

Optimal Tax Policy under Environmental Quality Competition

This paper studies the socially optimal emission and commodity tax policy when consumers are willing to pay a price-premium for environmentally friendlier variants of a commodity vertically differentiated in environmental quality. The first-best levels of quality can be obtained by a combination of a uniform ad valorem tax and an emission tax (or a subsidy for buying green products). The first-best emission tax is higher than the social valuation of the positive externality associated with average environmental quality. Regardless of environmentally conscious consumers, if only one instrument is available, the second-best emission tax is equal to the social valuation of the positive externality associated with average environmental quality. A uniform ad valorem tax increases welfare only if the social valuation of the positive externality associated with average environmental quality is low enough.     

Consumption taxes in monopolistic competition: a comment

We show that an ad valorem tax is better than an equal-revenue unit tax when consumers spend some fixed proportion of income on taxed goods, when firms use constant mark-up pricing, and entry and exit drive per-firm profit to zero. These key assumptions implies that ad valorem taxes are superior in oligopoly as well as monopolistic competition, showing that earlier results on taxes in monopolistic competition (Schröder in J Econ 83(3):281–292, 2004) are not due to the mode of competition, but rather are due to the functional forms used.     

The Comparison between Ad Valorem and Unit Taxes under Monopolistic Competition

This paper shows that the welfare dominance of ad valorem over unit taxes under imperfect competition, extends to a Dixit-Stiglitz-type monopolistic competition framework with differentiated products, increasing returns to scale, entry/exit and love of variety. This result is obtained, even though ad valorem taxation leads to increased firm exit compared to the equal-yield unit tax. Yet the smaller tax over-shift, occurring under ad valorem taxation, more than compensates this disadvantage.Acknowledgement Comments and suggestions from Anthony Atkinson, Jürgen Bitzer, Rainald Borck, David Collie, Jan G. Jørgensen and two anonymous referees are gratefully acknowledged.     

COMMODITY TAX STRUCTURE AND INFORMAL ACTIVITY

Commodity tax structure affects the firm's choice between formality and informality. An increase in the specific tax rate, relative to an equivalent increase in ad valorem taxation, makes informality attractive to more firms. Formality becomes attractive at lower levels of profits under ad valorem taxation. For both the maximization of welfare subject to a revenue constraint and the unconstrained maximization of revenue, the optimal rate of specific taxation is zero.     

Tax Effects in a Model of Product Differentiation: A Note

We investigate how unit (or specific) tax and ad valorem tax affect equilibrium location choice in a model of product differentiation, which includes Hotelling (linear-city) and Vickrey-Salop (circular-city) spatial models as special cases. We find that neither tax affects equilibrium location patterns as long as each firm has the same production cost. Two taxes can yield different location patterns under cost heterogeneity among firms.     

Correcting Market Failure Due to Interdependent Preferences: When Is Piecemeal Policy Possible?

Allowing for general utility interdependence and agent heterogeneity, we characterize taxes that will generate first best solutions in markets. We show the equivalence of tax corrections derived from the Marshallian and compensated demand approaches. Next we analyze the conditions that are required for the market failure to be corrected by: (1) specific indirect ad valorem taxes on commodities, (2) the same proportional tax rate on every commodity, and (3) a proportional income tax rate on each individual. The conditions are related to the restrictions necessary to have H synthetic consumers without externalities who replicate behavior of individuals with externalities.     

Tax effects on equilibrium locations

Using a Hotelling-type model with elastic demand functions and spatial discrimination, we show that, in contrast with previous results obtained with inelastic demand functions, neither ad valorem nor unit taxes are neutral for equilibrium locations. In fact, the higher is the tax rate the lower is the equilibrium distance between firms.     

Sound taxation? On the use of self-declared value

In the 16th century, foreign ships passing through the Sound had to pay ad valorem taxes, known as the Sound Dues. To give skippers an incentive to declare the true value of their cargo, the Danish Crown reserved the right to purchase it at the declared value. We show that this rule does not induce truth-telling, but does allow the authorities to effectively implement a given tax rate.     

Oligopoly and the redistribution of market share under commodity taxation

This paper examines the effect of ad valorem and specific commodity taxation on firm market share in a duopoly where firms have different costs. Two reasons suggested for these cost asymmetries are inter-firm differences in efficiency and differences in product quality. When cost differences are efficiency-based, then specific and ad valorem commodity taxation increases the market share of the lower-cost firm and decreases the market share of the higher-cost firm. If the cost difference results from differing product quality, the specific tax increases the market share of the high quality (higher-cost) firm and decreases the market share of the low quality (lower-cost) firm, whereas, the ad valorem tax has just the opposite effect.     

Location decisions of a polluting firm and the time consistency of environmental policy

This paper considers location decisions of a monopolist, who faces a tax on its emissions in the home country, under ex post that is, time consistent, and ex ante, that is precommitment, environmental policies. We show that the monopolist will relocate more often under ex post optimal emission taxes. A government which cannot commit to an ex ante emission tax and sets its tax ex post after abatement effort has been chosen, is unable to affect the monopolist’s location decision, because it cannot commit to strategically reduce its tax level in the first stage. Domestic welfare is often higher under ex post emission taxes whenever the monopolist relocates under both policy regimes. Otherwise, welfare is higher under government commitment to an ex ante emission tax level. Thus, government commitment to a policy is not always welfare improving.     

我国矿产资源价格重构中的税收效应分析

现阶段我国矿产资源价格扭曲是导致资源配置效率低下和环境污染的重要诱因。本文在标准的动态霍特林模型分析框架下,对税收与资源价格之间的关系进行理论分析,重点对矿产资源征税应采取从量税还是从价税作出解释。最后针对我国矿产资源价格改革中存在的诸多税收问题,提出资源税收进一步深化改革的政策建议。     

Welfare Effects of Commodity Taxation in Cournot Oligopoly

In the context of Cournot oligopoly with possibly asymmetric costs, this paper presents necessary and sufficient conditions for a small specific tax and a small ad valorem tax to increase total surplus. The paper also shows that a shift from a small specific tax to a small ad valorem tax, leaving the tax revenue unchanged, increases the total surplus.
JEL Classification Numbers: D43, H21, L13.     

Specific taxation,asymmetric costs,and endogenous quality

This paper shows how a specific tax—in contrast to an ad valorem tax—alters industry structure and firm-level performance in a monopolistic competition framework, where firms chose product quality endogenously and differ exogenously in productivity (i.e., marginal production efficiency). Industry equilibrium mechanisms and selection based on productivity play a significant role: A specific tax shifts market shares and profits toward firms with costs and prices above the industry average at the expense of low-cost firms. This reallocation of market shares releases a novel scale effect such that low-cost firms may quality downgrade, while high-cost firms always quality upgrade. There exists a parameter subspace, where this combines to a decrease on average quality for the industry. In comparison: An ad valorem tax only reduces the number of firms/varieties in the industry due to demand absorption, but affects neither firm-level performance nor industry structure.     

Commodity taxes under uncertainty

This paper considers the relative distorting effect on output of commodity taxes, specific and ad valorem, in a situation where a firm faces revenue uncertainty. It is shown generally that this effect depends both on the precise nature of the firm's revenue uncertainty and on the degree of its risk aversion. More specifically, the distorting effect of each tax is characterised for a selection of objective functions and uncertain environments. These characterisations are compared in order to show the influence of alternative specifications on the relative distorting effect.     

Ad valorem versus unit taxes: monopolistic competition, heterogeneous firms, and intra-industry reallocations

Real-world industries are composed from heterogeneous firms and substantial intra-industry reallocations take place, i.e. high productivity firms squeeze out low productivity firms. Previous tax-tool comparisons have not included these central forces of industry structure. This paper examines a general equilibrium monopolistic competition model with heterogeneous firms and intra-industry reallocations. We show that the welfare superiority of ad valorem over unit taxes under imperfect competition is not only preserved but amplified. The additional difference between the tools arises because unit taxes distort relative prices, which in turn reduces average industry productivity through reallocations (the survival and increased market share of lower productivity firms). Importantly, numerical solutions of the model reveal that the relative welfare loss from using the unit tax increases dramatically in the degree of firm heterogeneity.     

Do emission subsidies reduce emission? In the context of environmental R&D organization

This paper, which reexamines the Poyago-Theotoky model, provides additional investigation that was conducted under a corrected environmental damage parameter. As new findings, we obtain the following. First, social welfare under a time-consistent emission tax (emission subsidy) policy is always welfare-enhancing rather than the case of laissez-faire. Second, if the environmental damage parameter is sufficiently small, then the equilibrium emission tax rate is invariably negative. It is therefore an emission subsidy. Moreover, total emissions under the emission subsidy scenario become less than those under laissez-faire if the damage parameter is sufficiently small, and if the R&D cost is low. However, total emissions under the emission subsidy become greater than those under laissez-faire if the damage parameter is sufficiently small, and if the R&D cost is high.     

Effects of Carbon Dioxide Control Policy in China by Multi-Regional CGE Model

In recent years, China has faced tremendous pressure to reduce carbon dioxide emissions. At the COP 15 United Nations Climate Change Conference in Copenhagen in 2009, China committed itself to achieve a 40%–45% per GDP carbon dioxide emission reduction in the near future. To reach this goal, China is willing to adopt a series of new policies, including attempts to introduce a carbon tax, and to start an energy-resource-tax pilot program in the western provinces. For this research, we constructed a Multi-Regional Computable General Equilibrium model. Then we used six scenarios to evaluate the economic effects and effectiveness of energy-resource tax policy for control of carbon dioxide emissions for different regions of China. The main result of this research is the finding that an ad valorem energy resource tax can reduce carbon dioxide emissions in China. At the same time, fiscal policy might engender different effects in different regions of China. Additionally, this policy is more efficient for controlling petroleum and natural gas resources than it is for coal resources.     

Emission Taxes and Product Differentiation in the Presence of Foreign Firms

Industries characterized by differentiated products are important contributors of greenhouse gases and currently subject to market‐based policies such as emission taxes. In the context of developing countries, fears about foreign investment leaving the country are often used as an argument not to address industry emissions through emission taxes. This paper develops a Cournot model with product differentiation in the presence of abatement efforts where host and foreign firms are subject to an emission tax. The analysis indicates that abatement efforts and differences in pollution intensity coefficients across firms may play a significant role in the characterization of optimal policy. The analysis also suggests that the government may opt to encourage foreign, less pollution‐intensive firms via higher taxation. Additionally, this paper examines how an optimal emission tax may be adjusted as products become more differentiated; industry emissions may fall/rise as a result of more differentiated products. One important contribution of this paper is that it emphasizes the role of abatement efforts, product differentiation, and differences in pollution intensity coefficients across firms in the characterization of the optimal emission tax.