Comment on B. Carlén and B. Kriström: Are Climate Policies in the Nordic Countries Cost-Effective? In: L. Calmfors and J. Hassler, editors, Nordic Economic Policy Review 2019: Climate Policies in the Nordics. p. 148-151. Nordic Council of Ministers, 2019.


Working Papers

Directed Technical Change, Environmental Sustainability, and Population Growth

Abstract: Population growth has two potentially counteracting effects on pollution emissions:(i) more people implies more production and thereby more emissions, and (ii) more people implies a larger research capacity which might reduce the emission intensity of production, depending on the direction of research. This paper investigates how to achieve a given climate goal in the presence of these two effects. A growth model featuring both directed technical change and population growth is developed. The model allows for simultaneous research in polluting and non-polluting technologies. Both analytical and numerical results indicate that population growth is a burden on the environment, even when all research efforts are directed toward non-polluting technologies. Thus research subsidies alone cannot ensure environmental sustainability. Instead, the analysis shows that environmental sustainability requires pollution taxes and/or population control policies.

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Endogenizing the cap in a cap-and-trade system: Assessing the agreement on EU ETS phase 4 (with Ulrik R. Beck) [R&R]

Abstract: In early 2018, a reform of the world’s largest functioning greenhouse gas emissions cap-and-trade system, the EU Emissions Trading System (ETS), was formally approved. The reform changes the main principles of the system by endogenizing the previously fixed emissions cap. We show that the effective emissions cap is now affected by the allowance demand and therefore not set directly by EU policymakers. One consequence of this is that national policies that reduce allowance demand can reduce long-run cumulative emissions, which is not possible in a standard cap-and-trade system. Using a newly developed dynamic model of the EU ETS, we show that policies reducing allowance demand can have substantial effects on cumulative emissions. Our model simulations also suggest that the reform reduces aggregate emissions in both the short and long run, but the long-run impact is substantially larger. Yet, the reform has a small impact on the currently large allowance surplus.

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Optimal Energy Taxes and Subsidies under a Cost-Effective Unilateral Climate Policy: Addressing Carbon Leakage (with Peter Birch Sørensen) [Under review]

Abstract: We analyze how a country pursuing a unilateral climate policy may contribute to a reduction in global CO2 emissions in a cost-effective way. To do so its system of energy taxes and subsidies must account for leakage of emissions from the domestic to the foreign economy. We focus on leakage occurring via international trade in electricity and via shifts between domestic and foreign production of other goods. The optimal tax-subsidy scheme is based on an intuitive principle: Impose a uniform carbon tax on all additions to global emissions caused by changes in domestic production and consumption of energy, including additions to emissions occurring via shifts in international trade. Emissions from the sector exposed to foreign competition should be taxed at reduced rates to avoid excessive carbon leakage, and a part of the carbon tax on electricity should be levied at the consumer rather than the producer level to ensure taxation of the carbon content of imported electricity. Producers of renewables-based electricity should receive a subsidy to internalize their contribution to the reduction of global emissions. In other sectors emissions should be taxed at a uniform rate corresponding to the marginal social cost of meeting the target for emissions reduction. Simulations calibrated to data for the Danish economy suggest that redesigning energy taxes and subsidies to account for carbon leakage can generate a welfare gain.

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Testing R&D-Based Endogenous Growth Models

Abstract: R&D-based growth models are tested using US data for the period 1953-2014. A general growth model is developed which nests the model varieties of interest. The model implies a cointegrating relationship between multifactor productivity, research intensity, and employment. This relationship is estimated using cointegrated VAR models. The results provide evidence against the widely used fully endogenous variety and in favor of the semi-endogenous variety. Forecasts based on the empirical estimates suggest that the slowdown in US productivity growth will continue. Particularly, the annual long-run growth rate of GDP per worker converges to between zero and 1.1 pct.

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Directed Technical Change and Economic Growth Effects of Environmental Policy

Abstract: A Schumpeterian growth model is developed to investigate how environmental policy affects economic growth when environmental policy also affects the direction of technical change. In contrast to previous models, production and pollution abatement technologies are embodied in separate intermediate good types. A set of stylized facts related to pollution emission, environmental policy, and pollution abatement expenditures is presented, and it is shown that the developed model is consistent with these stylized facts. It is shown analytically that a tightening of the environmental policy unambiguously directs research efforts toward pollution abatement technologies and away from production technologies. This directed technical change reduces economic growth and pollution emission growth. Simulation results indicate that even large environmental policy reforms have small economic growth effects. However, these economic growth effects have relatively large welfare effects which suggest that static models and exogenous growth models leave out an important welfare effect of environmental policy.

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On the Plausible Case of Less-than-exponential Economic Growth

Abstract: A general R&D-based endogenous growth model nesting well-known models of exponential economic growth as well as a model exhibiting less-than-exponential economic growth is developed. The model is estimated using US data for the period 1960-2013, and the parameter estimates support the case of less-than-exponential economic growth.

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