Optimal control of pollutants with delayed stock accumulation

We study the optimal control of a pollutant that accumulates with a delay.We find that optimal paths are, in general, non-monotonic and oscillatory, but monotonic if the objective function is additively separable. Hence, using additively separable objective functions as an approximation to a general objective function may be a misspecification. With a numerical example we illustrate that an additively separable approximation performs considerably worse in delayed compared to instantaneous stock accumulation.additively separable objective, approximated objective, delayed optimal control, optimal pollution control

Now or Never: Environmental Protection under Hyperbolic Discounting

In this paper, we extend the well known result that hyperbolically discounting agents tend to postpone costs into the future. In a simple model we show that, without commitment to the ex ante optimal plan, no investment in environmental protection is undertaken over the whole time horizon, no matter whether the decision makers are naive or sophisticated, although investment seems optimal in the long run from every generations point of view. This result questions the application of hyperbolic discounting in cost-benefit analysis and gives rise to concern, as it is consistent with unsatisfactory policy performance in solving long-term environmental problems.environmental policy, environmental protection, hyperbolic discounting, intertemporal decision theory, procrastination, time-(in)consistency

Why do ICDPs fail? The relationship between subsistence farming, poaching and eco- tourism in wildlife and habitat conservation

In this paper we investigate the reasons why integrated conservation and development projects (ICDPs) fail to achieve their conservation goals. We develop a bio-economic model of open access land and wildlife exploitation, which is consistent with many farming and hunting societies living in close proximity to forest reserves in developing countries. We show that the ICDP creates incentives to conserve habitat and wildlife, but, in general, the socially optimal level of conservation cannot be achieved, because of externalities among the local communities. We show how a social planner can achieve the socially optimal levels of habitat and wildlife by a more encompassing tax/subsidy regime.bio-economic modelling, competing land-use, ecotourism, integrated conservation and development projects, poaching, wildlife and habitat conservation

The role of environmental and technology policies in the transition to a low-carbon energy industry

In a dynamic general equilibrium model we study the interplay between gradual and structural change in the transition to a low-carbon energy industry. We focus on the welfare-theoretic consequences of diverging social and private rates of time preference and a time-to-build feature in capital accumulation. Both features are particularly important in the transformation of energy systems. We show that only a combination of environmental and technology policies can achieve a socially optimal transition. We thus provide a new reason for environmental regulation to be complemented by technology policy such as a non-distortionary investment subsidy.environmental and technology policy, social vs. individual rates of time preference, time to build, gradual vs. structural technological change, energy industry

Political influence on non-cooperative international climate policy

We analyze non-cooperative international climate policy in a setting of political competition by national interest groups. In the first stage, countries decide whether to set up an international emission permits market, which only forms if it is supported by all countries. In the second stage, countries non-cooperatively decide on the number of tradable or non-tradable emission allowances, depending on the type of regime. In both stages, special interest groups try to sway the government in their favor. We find that (i) both the choice of regime and the level of aggregate emissions only depend on the aggregate levels of organized stakes in all countries and not on their distribution among individual interest groups, and (ii) an increase in lobbying influence by a particular lobby group may backfire by inducing a change towards the less preferred regime.non-cooperative climate policy; political economy; emissions trading; organization

The Effect of Kyoto Emission Targets on Domestic CO2 Emissions: A Synthetic Control Approach

We use recent developments in the empirics of comparative case studies to analyze the effect of binding emission targets under the Kyoto Protocol on the development of CO2 emissions of seven major Annex B countries. In particular, we investigate whether committing to a specific greenhouse gas emissions target had an effect on actual CO2 emissions of Australia, Canada, France, Germany, Great Britain, Italy and Japan by using a synthetic control approach. With the exception of Great Britain, we are not able to reject the hypothesis that there has been no effect of binding emission targets on actual emissions.Climate Policy; International Environmental Agreements; Kyoto Protocol; Synthetic Control Method

Gradual versus structural technological change in the transition to a low-emission energy industry: How time-to-build and differing social and individual discount rates influence environmental and technology policies

We develop a general equilibrium model to study the transition from an established polluting to a new clean energy technology. Therefore, we consider two distinctive features: (i) the creation of new productive capital exhibits a timeto-build property, and (ii) the social and individual rates of time preference differ. We derive necessary and sufficient conditions for investment in the new and for replacement of the established technology. We show that, in addition to the standard emission externality, a further market failure stemming from the differing discount rates arises, the extent of which positively depends on the time-lag in capital accumulation. Moreover, we show that in a mutually reinforcing way both market failures create less favorable circumstances for the introduction of the new technology compared to the social optimum. The paper thus provides an additional reason why environmental policy should be complemented by technology policy in the transition to a low-emission energy industry. --energy industry,gradual vs. structural technological change,rate of time preference,time-to-build

On the Design of Global Refunding and Climate Change

We design a global refunding scheme as a new international approach to address climate change. A global refunding system allows each country to set its carbon emission tax, while aggregate tax revenues are partially refunded to member countries in proportion to the relative emission reductions they achieve within a given period, compared to some given baseline emissions. In a simple model we show that a suitably designed global refunding scheme is self-enforcing and achieves the social global optimumclimate change mitigation, global refunding scheme, international agreements, self-enforcing mechanisms

International Emission Permit Markets with Refunding

We propose a blueprint for an international emission permit market such as the EU trading scheme. Each country decides on the amount of permits it wants to offer. A fraction of these permits is grandfathered, the remainder is auctioned. Revenues from the auction are collected in a global fund and reimbursed to member countries in fixed proportions. We show that international permit markets with refunding lead to outcomes in which all countries tighten the issuance of permits and are better off compared to standard international permit markets. If the share of grandfathered permits is sufficiently small, we obtain approximately socially optimal emission reductions.climate change mitigation, global refunding scheme, international permit markets, international agreements, tradeable permits

Growth and Welfare under Endogenous Lifetime

We develop a perpetual youth model to investigate how longevity affects economic growth and welfare. Life expectancy is determined by individuals’ investments in healthcare. We find that improvements in the healthcare technology always increase the steady state growth rate. Although the effect is small, even for large increases in longevity, welfare gains may be substantial depending on the type of the technological improvement. We identify two externalities associated with healthcare investments and provide a condition when healthcare expenditures are inefficiently low in the market equilibrium. Finally, we discuss our results with respect to alternative spillover specifications in the production sector.economic growth, endogenous longevity, healthcare expenditures, healthcare technology, quality-quantity trade-off