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.     

Optimal Timing of Climate Change Policy: Interaction Between Carbon Taxes and Innovation Externalities

This paper addresses the impact of endogenous technology through research and development (R&D) on the timing of climate change policy. We develop a model with a stock pollutant (carbon dioxide) and abatement technological change through R&D, and we use the model to study the interaction between carbon taxes and innovation externalities. Our analysis shows that the timing of optimal emission reduction policy strongly depends on the set of policy instruments available. When climate-specific R&D targeting instruments are available, policy has to use these to step up early innovation. When these instruments are not available, policy has to steer innovation through creating demand for emission saving technologies. That is, carbon taxes should be high compared to the Pigouvian levels when the abatement industry is developing. Finally, we calibrate the model in order to explore the magnitude of the theoretical findings within the context of climate change policy.      

Pollution Abatement Subsidies and the Eco-Industry

This paper considers the combination of pollution taxes and abatement subsidies when some polluting firms procure their abatement goods and services from an oligopolistic eco-industry. The regulator must here cope with two simultaneous price distortions: one that comes from pollution and the other which is caused by the eco-industry’s market power. In this context, we show that taxing emissions while subsidizing polluters’ abatement efforts cannot lead to first-best, but the opposite occurs provided it is the eco-industry’s output which is subsidized. When public transfers also create distortions, welfare can be higher if the regulator uses only an emission tax, but subsidizing abatement suppliers while taxing emissions remains optimal when the eco-industry is concentrated.     

Incentives to Diffuse Advanced Abatement Technology Under the Formation of International Environmental Agreements

We analyse the incentives for polluting firms to diffuse and adopt advanced abatement technology in a framework in which governments negotiate an international environmental agreement. These incentives crucially depend on whether the underlying environmental policy instrument is an emission tax or an emission quota. The results for the international setting fundamentally differ from those for the national setting that have been elaborated upon in the earlier literature. In particular, equilibrium diffusion and adoption of advanced abatement technology are not necessarily optimal under the tax regime and may be even lower than those under the quota regime.     

Do technology externalities justify restrictions on emission permit trading?

International emission trading is an important flexibility mechanism, but its use has been often restricted on the ground that access to international carbon credits can undermine the domestic abatement effort reducing the incentive to innovate and, eventually, lowering the pace of climate policy-induced technological change. This paper examines the economics that is behind these concerns by studying how a cap to the trade of carbon offsets influences innovation, technological change, and welfare. By using a standard game of abatement and R&D, we investigate the main mechanisms that shape these relationships. We also use a numerical integrated assessment model that features environmental and technology externalities to quantify how limits to the volume, the timing, and the regional allocation of carbon offsets affect climate policy costs and the incentive to invest in innovation and low-carbon technologies.Results indicate that, for moderate caps on the amount tradable emissions permits and sufficiently high technology spillovers, global innovation and technical change would increase and that this additional innovative effort could lead to economic efficiency gains. The numerical analysis confirms that when constraints are close to 15% of domestic abatement, efficiency losses are small because they are partly compensated by more technological spillovers and lower energy prices. Under a broad range of parameters, restrictions are costly for the constrained countries, but always beneficial for unconstrained ones.     

行业视角下减排成本估算及减排路径研究

碳达峰碳中和是中国经济发展环境治理的战略目标,减排成本与减排路径是该战略实施中两大现实问题。基于行业视角,利用投入产出方法,对行业减排成本、技术减排效应及减排路径展开研究,基本结论如下：①行业减排成本差异大,整体减排成本逐年上升。在三个代表性年份行业最高与最低减排成本相差40-60倍,减排成本绝对差值在1500-3000$/t。在2000-2010年间, 32个行业减排成本均有不同程度的上升, 全社会整体减排成本上升了56.98%。②技术进步的减排贡献较大,部分行业技术减排有限。在产出固定假设下,2000-2010年技术进步实现累计减排57.09亿t,累计技术减排率达到47.88%；但在旅游、住宿餐饮等行业技术减排率为负,技术因素导致的排放不减反增。③行业减排路径应遵循从高碳到低碳的顺序。基于减排成本与技术减排两大因素的减排路径规划显示,优先和重点减排行业主要集中在能源生产供给、加工制造、交通运输、采矿及设备制造等高能耗高排放行业；可相对延后和非重点减排行业主要为食品烟草等传统加工制造业以及金融、房地产等现代服务业。     

The Timing of Environmental Policy: A Note on the Role of Product Differentiation

We examine the role that product differentiation can play in the design of environmental policy under full commitment and no commitment on the part of the environmental regulator. We consider a setting with two firms selling a differentiated product which generates pollution through emissions. Firms can reduce their emissions by undertaking abatement activities while an environmental regulator taxes emissions. The main results are: (1) When products are highly differentiated, the optimal time-consistent (no commitment) tax is always lower than the optimal pre-commitment tax. As the degree of product differentiation decreases, for relatively efficient abatement technology and high damages, the time-consistent emission tax exceeds the optimal pre-commitment one. (2) Abatement when product differentiation is extensive is higher under the time-consistent regime unless the abatement technology is extremely efficient. The same ranking applies to social welfare. However, as products become more and more similar, these results are (partially) reversed and pre-commitment could lead to both higher levels of abatement and welfare.     

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.     

中国制造业环境规制对技术创新影响的阶段性差异与行业异质性研究

首先,将技术创新划分为技术研发和技术转化两阶段,应用CES生产函数分阶段推导环境规制与技术创新的数理关系。其次,根据污染排放强度将中国制造业28个细分行业划分为重度污染型、中度污染型及轻度污染型3种类型,以2003-2012年行业面板数据为样本,构建分阶段分行业的计量回归模型进行环境规制对技术创新的实证检验。数理推导证明：环境规制与企业技术研发和技术转化在数理上均存在正相关关系。实证检验发现：①环境规制对中国制造业技术研发专利成果和技术转化新产品生产具有显著促进作用,波特假说在制造业整体上得到验证;②环境规制对中度污染行业、轻度污染行业的技术创新具有显著促进作用,但对重度污染行业的影响并不显著,波特假说存在明显的行业异质性。最后,针对环境规制对技术创新影响的阶段性和行业异质性提出了相关政策建议。     

人力资本、绿色科技创新与长江经济带全要素碳排放效率

基于1999—2019年长江经济带面板数据,运用全局超效率SBM模型、拓展的STIRPAT模型、中介效应模型和门槛模型,考察人力资本、绿色科技创新与全要素碳排放效率之间的关系。研究结果表明,人力资本积累在直接促进长江经济带全要素碳排放效率优化的同时,通过绿色科技创新发挥间接促进作用。为进一步推动长江经济带全要素碳排放效率提升,加快建成引领全国经济高质量发展的主力军,建议以绿色科技创新为引领,促进人力资本不断积累,全面激发长江经济带绿色低碳转型发展活力。     

The Role of Investment in Environmental Lobbying Contests

This paper establishes that a lobbying stage following investment decisions regarding abatement technology may imply a positive strategic effect of investment, pointing to relatively more investment in pollution abatement technologies than without lobbying. The intuition is that polluting firms may choose to implement more advanced abatement technology as a credible commitment device in order to lower the investment of environmentalists in the lobbying contest that will ultimately determine whether or not an emissions tax is introduced.     

Regulating a Polluting Oligopoly: Emission Tax or Voluntary Agreement?

This paper compares, in a polluting oligopoly, an emission tax and a form of environmental policy called voluntary agreement (VA). Here there are two ways of reducing pollution: output contraction and end‐of‐pipe abatement. Given the imperfect competition, firms’ reaction to the tax is sub‐optimal. They reduce output excessively in order to raise the price and do not abate enough. The VA is a take‐it‐or‐leave‐it contract on abatement effort, offered to the firms with the threat of a tax. It has a limited effect on output and always allows higher abatement than the tax. We find that this kind of VA may be more efficient than the tax in a concentrated industry, when pollution is not too harmful and when the abatement technology is rather efficient and cheap.     

Optimal combination of innovation and environmental policies under technology licensing

Under what conditions will a carbon tax encourage environmental innovation? Can a regulator design an optimal environmental policy to reduce emissions and to promote clean technologies? This paper studies optimal environmental policy in the situation where a monopoly innovator develops and licenses clean production technologies to downstream polluting firms. We find that (i) a higher emission tax will encourage innovation when the burden of the tax payment in the polluters' costs and/or the price-elasticity of the demand for polluting goods are small, (ii) the innovation-inducing effects of emission tax are inversely related to the emission-reduction (Pigouvian) effects of the tax, and (iii) the social optimum can be achieved by the mix of tax and subsidy. We also show that if the policy instrument is limited to the tax, the second-best tax rate would lie between the marginal damage and the first-best rate. By performing numerical simulations, we also demonstrate that the optimal mix of the emission tax and R&D subsidy can have “double dividend” benefits.     

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.     

How Large are the Welfare Gains from Technological Innovation Induced by Environmental Policies?

This paper examines whether the welfare gains from technological innovation that reduces future abatement costs are larger or smaller than the Pigouvian welfare gains from optimal pollution control. The relative welfare gains from innovation depend on three key factors—the initially optimal level of abatement, the speed at which innovation reduces future abatement costs, and the discount rate. We calculate the welfare gains from innovation under a variety of different scenarios. Mostly they are less than the Pigouvian welfare gains. To be greater, innovation must reduce abatement costs substantially and quickly and the initially optimal abatement level must be fairly modest.     

Human Development at Risk: Economic Growth with Pollution-Induced Health Shocks

Risks to human health stemming from polluted air, water, and soil are substantial, especially in the rapidly growing economies. The present paper develops a theoretical framework to study an endogenously growing economy which is subject to pollution-induced health shocks with the health status being an argument of the welfare function. Pollution, arising as a negative externality from production, adversely and randomly affects the regeneration ability of a human body leading to a decline in the overall health status of the population. We include two types of uncertainty surrounding the health status: continuous small-scale fluctuations, driven by the Wiener process, and large-scale shocks or epidemics, driven by the Poisson process. We derive closed-form analytical solutions for the optimal abatement policy and the growth rate of consumption. Devoting a constant fraction of output to emissions abatement delivers the first-best allocation. This fraction is an increasing function of total factor productivity, polluting intensity of production, and damage intensity of both continuous and jump-type shocks. A higher frequency of jumps also calls for more vigorous abatement policies. By contrast, the optimal growth rate of the economy is decreasing in the frequency and intensity of shocks and in the polluting intensity of output. The efficiency of abatement technology has, in general, an ambiguous bearing on both the growth rate and on the abatement share due to the opposing forces of the direct and indirect effects.     

From command-and-control to market-based environmental policies: Optimal transition timing and China’s heterogeneous environmental effectiveness

Despite the rich literature on command-and-control and market-based environmental policies, the transition between them has received relatively less attention. This paper identifies that there exists an optimal transition timing from command-and-control policies to market-based policies by analyzing the trade-off between the abatement cost and innovation compensation effects of environmental regulations, and the optimal transition timing occurs when the marginal opportunity cost of pollution abatement equals the marginal output of capital input. Using province-level data of 30 regions in China from 2007 to 2015, we measure environmental efficiency by the slack-based model with desirable and undesirable output, and adopt the spatially adaptive semi-parametric model to carry out our empirical research, which shows that command-and-control policies, rather than market-based policies, promote China’s environmental efficiency. Enhancing investment in technological innovation contributes to improving environmental efficiency for both types of policies. Finally, the effect of such policies on environmental efficiency remains heterogeneous across regions.     

基础研究发展对技术创新的影响：基于最优研发结构视角

基于1998-2019年中国省级层面数据，从最优研发结构视角实证检验基础研究发展对技术创新的影响。结果发现，基础研究发展与技术创新之间呈倒U型关系，存在一个最优基础研究占比。基础研究与应用研究融合发展有利于推动技术创新；在不同经济发展阶段，为促进技术创新所要求的最优基础研究占比不同，东部地区所要求的最优基础研究占比高于中西部地区；任何偏离最优基础研究占比的实际基础研究占比都会拖累技术创新。东部地区实际基础研究占比低于其最优基础研究占比的幅度大，因此东部地区技术创新损失程度高于中西部地区。     

智慧城市建设与城市碳排放：基于数字技术赋能路径的检验

智慧城市作为数字时代技术赋能型城市发展的新模式、新趋势,对我国实现低碳转型具有关键性作用。基于2006—2019年我国223个城市面板数据,实证研究智慧城市建设对城市碳排放的影响效应。研究发现：(1)智慧城市建设显著降低了城市碳排放,在引入PSM-DID、空间DID等模型进行稳健性检验后该结论依然成立;(2)智慧城市通过数字技术创新的直接路径和“数字技术创新→产业结构升级”的间接路径影响城市碳排放;(3)在人力资本、资金、物质越集聚的城市,数字技术赋能路径对城市碳减排的正向调节作用越显著。上述研究对我国实现碳达峰碳中和、城市实现数字赋能与低碳引领的双轮驱动发展具有重要现实意义。     

Emissions abatement R&D: Dynamic competition in supply schedules

This paper investigates the optimal environmental policy (the mix of emissions tax and research and development [R&D] subsidy) in a dynamic setting when two firms, producing differentiated products, compete in the output market over time. Firms compete in a differential game setting over supply schedules, which encompasses a continuum of imperfect competition equilibria from Bertrand to Cournot. Although production generates environmentally damaging emissions, firms can undertake R&D that has the sole purpose of reducing emissions. In addition to characterizing the optimal policy, we examine how the optimal tax and subsidy, and the optimal level of abatement, change as competition intensifies, as the dynamic parameters change, and as the investment in abatement technology changes. In this setting, competition increases welfare through its impact on the final goods price. However, lower prices result in larger quantities and more pollution. Our key contribution is to show how the impact of increased competition on welfare depends on the extent of the market and the nature of preferences and technology.