I am Principal Investigator in a collaborative two-year interdisciplinary research project on "Measuring the economic, environmental and climate effects of the Danish Tripartite Agreement (Aftale om et Grønt Danmark)". The project involves research teams from the Department of Economics and the Department of Food and Research Economics at the University of Copenhagen and the Research Institute for Danish Economic Analysis and Modelling (DREAM). Here is a brief description of the project:
The Tripartite Agreement "Aftale om et Grønt Danmark" adopted by the Danish Parliament in November 2024 will lead to land use changes in Denmark on a scale not seen since the second half of the 19th century. The agreement provides incentives for farmers to adopt more climate-friendly methods of production and, depending on its implementation, it could lead to significant improvements in water quality and protection of biodiversity as well as better air quality and improved conditions for outdoor life. This research project will apply state-of-the art methods and provide new analytical tools to estimate the economic and environmental effects of the Tripartite Agreement under alternative scenarios for its implementation, accounting for any modifications to the agreement decided by the Danish parliament. A major contribution of the project will be to link an environmental and climate economic model of the Danish economy (GreenREFORM) to a detailed model of Danish land use and its environmental consequences (TargetEcon). This will provide a powerful new analytical tool allowing an estimation of the effects of the Tripartite Agreement on the macroeconomy and the economic effects on individual sectors in the economy, including primary agriculture and the food industry, as well as the detailed effects of the agreement on the environment and climate, accounting for changes in land use and economic activity. The project will also provide estimates of the non-market benefits for the Danish population from the improvements to water quality, air quality, biodiversity and opportunities for recreation under alternative scenarios for implementation of the Tripartite Agreement.
The project is supported by a grant from the Novo Nordisk Foundation.
I am also involved in a related project on "Agriculture, Land Use, and Optimal Second-Best Environmental and Climate Policy with Greenhouse Gas Leakage", supported by the Green Solutions Centre at the University of Copenhagen. The project is joint work with Peter Kjær Kruse-Andersen in the Department of Economics and Wusheng Wu and Francesco Clara in the Department of Food and Resource Economics.
In another project joint with Rasmus Kehlet Skjødt Berg entitled "The National Carbon Price and Welfare on Alternative Paths Towards Net Zero Emissions" we are investigating the welfare effects of alternative pathways towards net zero CO2e-emissions in an open economy. The key question is: How much welfare is lost by following a simple but transparent policy rule rather that the optimal time path for the domestic carbon tax? Our findings are described in this working paper.
In recent years I have been co-directing two major research projects in Environmental Economics which have now come to fruition:
GREEN NET NATIONAL ACCOUNTING IN THEORY AND PRACTICE
This project developed a measure of Denmark's Green Net National Income (GNNI) and estimated its evolution over time. This was done by adjusting the Gross Domestic Product (GDP) recorded in the National Accounts for the value of the environmental and ecosystem services consumed by Danish residents over the year and for the change in the value of the stocks of Denmark's exhaustible and renewable resources, stocks of pollution, and other forms of natural capital. These adjustments of the conventional GDP highlight the importance of environmental goods and services for the welfare of Danish citizens and indicate whether Danish economic growth takes place at the expense of the environment. The project involved collaboration with Copenhagen University's Department of Food and Resource Economics, the Danish Centre for Environment and Energy at Aarhus University and Statistics Denmark's department for Green National Accounts. The project is documented in detail the following book volume on Routledge edited by me with the title: Green National Accounting in Theory and Practice - From GDP to the Green GDP. An English summary of the main findings in the project is provided here. A more comprehensive overview in Danish is given in this special issue of the journal Økonomi & Politik.
THE GREEN REFORM MODEL: A Model of the Interaction of the Environment and the Danish Economy
In collaboration with Head of Research Peter Stephensen and Project Director Jens Sand Kirk from the DREAM modelling group, I have been co-directing the work to develop the GREEN REFORM model which is a large scale computable general equilibrium model of the Danish economy designed to simulate the environmental effects of Danish economic activity and the economic effects of policy interventions to meet the targets for Danish environmental, energy and climate policy. The GREEN REFORM model has been praised by the OECD as an example for other countries to follow (oecd_introductory-note-integrating-climate-into-macroeconomic-modelling). The GREEN REFORM modelling project involves a large number of collaborators; more information on the project can be found here: https://dreamgroup.dk/greenreform/. An example of an application of the GREEN REFORM model is given here.
The national carbon price and welfare on alternative paths towards net zero emissions: Simple versus optimal policy rules (with Rasmus Kehlet Skjødt Berg). CESifo Working Paper 12101, August 2025.
Beyond natural capital accounting: Revitalizing Green GDP (with Jette Bredahl Jacobsen and Ole Gravgård Pedersen). August 2025.
The basic environmental economics of the circular economy. EPRU Working Paper Series 2017-04, Department of Economics, University of Copenhagen.
The effects of unilateral climate policy towards agriculture: A case study of Denmark (with Ulrik Beck, Asbjørn Kehlet Berg, Simon Christiansen, Cecilie Løchte Jørgensen, Jens Sand Kirk, Louis Birk Stewart and Peter Philip Stephensen). Journal of Agricultural Economics, 2025 ().
Optimal unilateral climate policy with carbon leakage at the extensive and the intensive margins (with Peter Kjær Kruse-Andersen). Scandinavian Journal of Economics , 2024.
National climate targets under ambitious EU climate policy (with Frederik Silbye). Nordic Economic Policy Review 2023 .
Optimal climate policy in EU frontrunner countries: coordinating with the EU ETS and addressing leakage (with Peter Kjær Kruse-Andersen). Climate Policy, November 2022.
Optimal energy taxes and subsidies under a cost-effective unilateral climate policy: Addressing carbon leakage (with Peter Kjær Kruse-Andersen). Energy Economics 109 (2022) 105928.
Barriers and opportunities in developing and implementing a Green GDP (with Jens Hoff and Martin Rasmussen). Ecological Economics 181 (2021) 106905.
Danish climate policy: Past achievements and future challenges. Ch. 15 in F. Caselli, A. Ludwig, and R. van der Ploeg (eds.), No-Brainers and Low-Hanging Fruit in National Climate Policy, CEPR Press, 2021.
Environment, energy, and climate policy: From energy supply to climate gases. Ch. 39 in P. Munk Christiansen, J. Elklit & P. Nedergaard (eds.), The Oxford Handbook of Danish Politics, Oxford University Press, 2020.
National climate policies and the European Emissions Trading System (with Frederik Silbye). Nordic Economic Policy Review 2019, 63-101.
From the linear to the circular economy: A basic model. Public Finance Analysis 74 (2018), 71-87.
The interaction of actual and fundamental house prices: A general model with an application to Sweden (with U. Michael Bergman). Journal of Housing Economics 54, 101792, 2021.
Taxation and the optimal constraint on debt finance: why a comprehensive business income tax is suboptimal. International Tax and Public Finance 24, 731-753, 2017.
Measuring the deadweight loss from taxation in a small open economy: A general method with an application to Sweden. Journal of Public Economics 117, 115-124, 2014.
Efficient redistribution of lifetime income through welfare accounts. Fiscal Studies 33, 1-37, 2012 (with A. Lans Bovenberg and Martin Ino Hansen).
Optimal social insurance with linear income taxation. Scandinavian Journal of Economics 111, 251-275, 2009 (with A. Lans Bovenberg).
The effects of tax competition when politicians create rents to buy political support. Journal of Public Economics 92, 1142-1163, 2008 (with Wolfgang Eggert).
Neutral taxation of shareholder income. International Tax and Public Finance, 12, 2005.
International tax coordination - regionalism versus globalism. Journal of Public Economics, 88, 2004.
Improving the Equity-Efficiency Trade-Off: Mandatory Savings Accounts for Social Insurance. International Tax and Public Finance, 11, 2004 (with A. Lans Bovenberg).
Labour tax reform, the good jobs and the bad jobs. Scandinavian Journal of Economics, 106, 2004 (with Henrik Kleven).
Optimal taxation with household production, Oxford Economic Papers, 52, 2000 (with Henrik Kleven and Wolfram F. Richter).
The case for international tax coordination reconsidered, Economic Policy, no. 31, October 2000.
Fra BNP til det Grønne BNP – Hvorfor og hvordan? Økonomi & Politik, vol. 97, nr. 1, 5-14.
Nobelprisen i økonomi 2018: Økonomisk vækst og klimaforandringer. Samfundsøkonomen no. 1, 2020.
Finanskrisen og den økonomiske videnskab. Nationaløkonomisk Tidsskrift (Danish Journal of Economics), 2011.
As a member of the Norwegian government tax reform committee in 2021-2022 I wrote two appendices to the committee's report, as a follow up on my article on "Neutral taxation of shareholder income" in International Tax and Public Finance, 12, 2005, which proposed a Rate-of-Return Allowance in the base for the taxation of shareholder income; a measure included in the Norwegian tax reform of 2005-2006 and later also proposed in the British Mirrlees Review.
Here are the two appendices (in Danish):
"Om aksjonærmodellens betydning for selskabernes kapitalomkostning".