Dynamic optimal control of pollution abatement under emissions permit banking

In a recent work, Dragone et al. (2010) modeled an optimal control model of pollution abatement, and investigated the adoption of a tax levied on the firm's instantaneous contribution to the accumulation of pollution. In this paper, we extend the work of Dragone et al. (2010) by providing a dynamic optimal control model of pollution abatement with emissions permits banking, where the firm is allowed to purchase, sell and bank emissions permits given a finite planning horizon of length. Our objective is to find the optimal levels of the production, the pollution abatement investment and the quantity of emissions permits bought or sold in continuous time through the use of optimal control theory. We illustrate the results with a numerical example.     

Dynamic modelling of pollution abatement in a CGE framework

This paper deals with the specification of pollution abatement in dynamic computable general equilibrium (CGE) models and analyses the dynamic feedback mechanisms between economy and abatement in the context of environmental policy. A Ramsey-type economic model is presented, in which bottom-up technical and economic information on abatement techniques is integrated in a top-down dynamic CGE context. The practical suitability of the specification is illustrated by an empirical application for climate change and acidification in the Netherlands. The results show that a mixture of some slowdown of economic growth, a substantial restructuring of the economy and implementation of most technical abatement measures is optimal.     

Environmental cost-benefit analysis of alternative timing strategies in greenhouse gas abatement: A data envelopment analysis approach

Assessing the benefits of climate policies is complicated due to ancillary benefits: abatement of greenhouse gases also reduces local air pollution. The timing of the abatement measures influences both the economic costs and ancillary benefits. This paper conducts efficiency analysis of ten alternative timing strategies, taking into account the ancillary benefits. We apply the approach by Kuosmanen and Kortelainen [Valuing Environmental Factors in Cost-Benefit Analysis Using Data Envelopment Analysis, Ecological Economics 62 (2007), 56-65], which does not require prior valuation of the environmental impacts. The assessment is based on synthetic data from a dynamic applied general equilibrium model calibrated to The Netherlands. Our assessment shows that if one is only interested in GHG abatement at the lowest economic cost, then equal reduction of GHGs over time is preferred. If society is willing to pay a premium for higher ancillary benefits, an early mid-intensive reduction strategy is optimal.     

Who should bear the administrative costs of an emissions tax?

All environmental policies involve costs of implementation and management that are distinct from pollution sources’ abatement costs. In practice, regulators and sources usually share these administrative costs. We examine theoretically an optimal policy consisting of an emissions tax and the distribution of administrative costs between the government and regulated sources of pollution. Our focus is on the optimal distribution of administrative costs between polluters and the government and the optimal level of the emissions tax in relation to marginal pollution damage. We demonstrate how the policy variables affect aggregate equilibrium administrative costs and show that these effects are generally indeterminate, as is the effect of the distribution of administrative costs on aggregate emissions. Consequently, the optimal sharing of administrative costs and whether the optimal emissions tax is higher or lower than marginal damage depend on specific contexts.     

Environmental Abatement and the Macroeconomy in the Presence of Ecological Thresholds

We study the environmental and economic effects of public abatement in the presence of multiple stable steady-state ecological equilibria featuring reversible hysteresis. The isocline for the stock of pollution possesses two stable branches. Assuming that the ecology is initially located on the upper (high pollution) branch of the isocline, a simple time-invariant temporary abatement policy can be used to steer the environment from the high- to the low-pollution equilibrium. In all models considered in this paper, a “cold turkey” abatement policy is optimal within the class of stepwise policies, i.e. the largest feasible shock should be administered for the shortest possible amount of time. The cold-turkey result is robust to alternative models for the economic system, although there is a capital feedback effect that either helps or hinders the speed of transition to the low-pollution equilibrium.     

On the dynamics of renewable resource harvesting and pollution control

The paper presents a dynamic partial equilibrium model which combines optimal renewable resource harvesting and optimal pollution control. Pollution accumulates as a slowly decaying stock and is assumed to affect the growth and the quality of the renewable resource stock. The aim is to maximize a social welfare functional which gives the present value of the difference between natural resource benefits and pollution control costs. The existence, uniqueness and the dynamic properties of the steady states are investigated. The analysis also gives a general result concerning the steady state of any two state variable optimal control problems.     

Rethinking the optimal level of environmental quality: justifications for strict environmental policy

Traditional environmental theory suggests that the optimal level of a pollution emission occurs when the marginal damage created by the emissions is equal to the marginal cost of reducing the emissions. We argue that the benefits from reducing pollution should be much more broadly defined to include at least three other sources of benefits. First, we develop a game-theoretic model in which firms may under-invest in cost-saving ‘green technologies’. Second, we demonstrate that consideration of future damages and abatement costs leads to a lower current optimal pollution level than that obtained in traditional models. Finally, we show that ecological complexity creates indirect pathways by which greater pollution increases the likelihood of generating irreversible environmental damage. This broader definition of the benefits of pollution abatement yields an optimal level of pollution that may actually be less than the level at which conventionally-measured marginal damages are equal to marginal abatement costs. Thus, environmental policy should be stricter.     

Investment and emission control under technology and pollution externalities

This paper studies incentives to develop advanced pollution abatement technology when technology may spillover across agents and pollution abatement is a public good. We are motivated by a variety of pollution control issues where solutions require the development and implementation of new pollution abatement technologies. We show that at the Nash equilibrium of a simultaneous-move game with R&D investment and emission abatement, whether the free rider effect prevails and under-investment and excess emissions occur depends on the degree of technology spillovers and the effect of R&D on the marginal abatement costs. There are cases in which, contrary to conventional wisdom, Nash equilibrium investments in emissions reductions exceed the first-best case.     

CO2 abatement policy with learning-by-doing in renewable energy

This paper analyzes the implications of CO₂ abatement when there is endogenous technological change in renewable energy. A multi-sector numerical general equilibrium model for Denmark is proposed to reflect two basic assumptions about technological progress in renewable energy. First, there is learning-by-doing and unit costs of production are a decreasing function of cumulated output. Second, technological progress only benefits new vintages of capital. The learning-by-doing process is calibrated to match current projections for technological progress in wind-based electricity. The implications are a marked reduction in the total and marginal cost of abatement and a decline in the optimal level of near-term abatement.     

Optimal environmental taxation and enforcement policy

We study the optimal environmental taxation and enforcement policy when (i) the regulator does not know the firms’ abatement costs, (ii) penalties for tax evasion are limited, and (iii) monitoring of pollution is costly. We show that the threat of being audited alter the usual firms’ incentives to over-estimate their abatement costs. In particular, depending on the firms’ abatement costs, the optimal policy may involve over or under-deterrence compared to the full information outcome. We then investigate the properties of a pollution standard. We show that this policy comes close to an environmental tax once the economic incentives of the accompanying enforcement policy are considered.     

Environmental regulations and innovation activity in UK manufacturing industries

We examine the relationship between environmental regulations and innovation, using data from UK manufacturing industry during 2000-2006. We estimate a dynamic model of innovation behaviour, and explicitly account for the likely endogeneity of our measure of the stringency of environmental regulations (pollution abatement costs). Our results indicate that while on the one hand environmental R&D and investment in environmental capital are stimulated by greater pollution abatement pressures, on the other hand there is not a positive impact of environmental regulation on total R&D or total capital accumulation. We find some evidence that this is because more stringent environmental regulations directly lower the optimal expenditure on non-environmental innovations. In addition, we find that environmental R&D may crowd out non-environmental R&D, although there is no evidence that environmental capital crowds out non-environmental capital.     

On a Fundamental Advantage of Permits Over Taxes for the Control of Pollution

We extend the tax versus permits literature by considering permit supply functions and pollution tax functions that are generalizations of the usual constant permit supply and constant pollution tax rate. In our model, pollution is not uniformly mixed and the regulator is uncertain about the polluting firms’ abatement costs. We determine the optimal permit supply functions and the optimal pollution tax functions. Using these functions, we show that permits lead unambiguously to lower total expected costs than taxes. We analyze the magnitude of this difference for a simple model of climate change. By relating the optimal permit supply functions to Weitzman (Am Econ Rev 68:683–691, 1978) we provide a new interpretation of his results.     

The Timing and Strategic Role of Self-Protection

Self-protection has private goods characteristics as it reduces own exposure to pollution given a certain level of pollution. We study the effect of timing self-protection before, after or simultaneously with abatement. We find that self-protection when timed before abatements has strategic effects. In this case self-protection, shifts the second stage subgame perfect Nash equilibrium of abatements such that own contributions of abatement are decreased and those of the other country are increased. Thereby shifting future abatement costs to the other country. When countries cooperate only on abatement, the incentives to shift future abatement costs are greater. Contrary to, intention, cooperation on abatement may in fact worsen environmental quality if it does not include self-protection.     

Random wastes,imperfect monitoring and environmental quality standards

This paper considers a firm's choice of optimal pollution abatement strategy in an environment where pollution licences are purchased through a market and a fine is levied for pollution in excess of the licences held. The pollution associated with any level of abatement is stochastic and the authority monitors pollution via a random sample of observations. Firms choose cost-minimising values for the mean and variance of emissions and the authority selects its sample size and the number of licences issued to achieve an exogenous level of environmental quality with abatement costs and monitoring costs at a minimum level.     

Pollution standards, technology investment and fines for non-compliance

In this paper, we analyze whether it is socially desirable that fines for exceeding pollution standards depend not only on the degree of non-compliance but also on technology investment efforts by the polluting firms. For that purpose, we consider a partial equilibrium framework where a representative firm chooses the investment effort and the pollution level in response to an environmental policy composed of a pollution standard, an inspection probability and a fine for non-compliance. We find that the fine should strictly decrease with the investment effort when (i) there are administrative costs of sanctioning; (ii) the optimal policy induces non-compliance; and (iii) either the fine is sufficiently convex in the degree of non-compliance or the investment effort decreases marginal abatement costs significantly.     

Supplementing Domestic Mitigation and Adaptation with Emissions Reduction Abroad to Face Climate Change

In this paper we focus on a long-term dynamic analysis of the optimal adaptation/mitigation mix in the presence of a pollution threshold above which adaptation is no longer efficient. We account for accumulation in abatement capital, greenhouse gases, and adaptation capital in order to better capture the arbitrage between abatement and adaptation investments. Pollution damages arise from the emissions due to the country consumption but also from the emissions of the rest of the world (ROW). A pollution threshold is then introduced, above which adaptation is no longer efficient. We obtain that if this threshold is lower than the steady-state level of pollution, there is no way for the modelled economy to avoid it. In particular, such a situation will appear if the ROW’s emissions are high. We then show that CDM may be a means to avoid a pollution threshold above which adaptation becomes of no use.     

Market power,private information,and the optimal scale of pollution permit markets with application to North Carolina's Neuse River

We extend the analysis of optimal scale in pollution permit markets by allowing for both market power and private information. We characterize the total costs (abatement costs and damages) under market power and private information and compare them to total costs under competition. It is possible for both market power and private information to lead to lower total costs than competition, but generally the differences between the three market structures will be small. We also conduct an optimal scale analysis of nitrogen pollution from waste water treatment plants (WWTP) into North Carolina's Neuse River System. An economic model of damages and abatement costs is integrated with a hydro-ecological model of nitrogen flow through the Neuse. We determine the optimal number of trading zones and allocate the WWTP into these zones. Under the most likely regulatory scenario, we find cost savings of 1.55 million dollars per year under the optimal market design relative to the typical 303(d) regulation in which the WWTP are not allowed to trade.     

Health effects and optimal environmental taxes

The literature on environmental taxation in the presence of pre-existing distortionary taxes has shown that interactions with these distortions tend to raise the cost of an environmental tax, and thus that the optimal environmental tax is less than marginal environmental damages. A recent paper by Schwartz and Repetto (2000) challenges this finding, arguing that the health benefits from reduced pollution will also interact with pre-existing taxes, and may cause the optimal environmental tax to exceed marginal damages.Schwartz and Repetto’s analysis represented health effects implicitly in the utility function. In contrast, the present paper explicitly represents health effects in an analytically tractable general equilibrium model. This model shows that interactions with health effects from pollution actually will tend to reduce the optimal environmental tax, contradicting, Schwartz and Repetto’s conclusion. This demonstrates the usefulness of explicitly modeling health effects, and it reinforces the general notion that tax-interactions tend to raise the costs of an environmental tax.     

Environmental Degradation,Longevity, and the Dynamics of Economic Development

I construct a two-period overlapping generations model in which longevity is positively affected by public spending on health services and negatively affected by pollution. It is shown that the parameters which determine the extent of environmental degradation (i.e., emission rate and pollution abatement) may also represent additional factors affecting the dynamics of the economy, the likelihood of multiple (non-trivial) steady-state equilibria and the emergence of poverty traps. The distribution of public spending between public health care and pollution abatement that maximizes equilibrium income is also derived. This distribution of spending minimizes the threshold which the economy needs to surpass in order to avoid a poverty trap while, under certain circumstances, it can maximize equilibrium welfare as well.     

Optimal Timing of CCS Policies with Heterogeneous Energy Consumption Sectors

Using the Chakravorty et al. (J Econ Dyn Control 30:2875–2904, 2006) ceiling model, we characterize the optimal consumption paths of three energy resources: dirty oil, which is non-renewable and carbon emitting; clean oil, which is also non-renewable but carbon-free thanks to an abatement technology, and solar energy, which is renewable and carbon-free. The resulting energy-mix can supply the energy needs of two sectors. These sectors differ in the additional abatement cost they have to pay for consuming clean rather than dirty oil, as Sector 1 (industry) can abate its emissions at a lower cost than Sector 2 (transport). We show that it is optimal to begin by fully capturing Sector 1’s emissions before the ceiling is reached. Also, there may be optimal paths along which the capture devices of both sectors must be activated. In this case, Sector’s 1 emissions are fully abated first, before Sector 2 abates partially. Finally, we discuss the way heterogeneity of abatement costs causes sectoral energy price paths to differ.