model of economic growth in the tradition of Robert Solow as a general equilibrium model with decentrally optimizing agents and market clearing conditions in an article published in German in 1980 and two years later in English, and before similar work by Chamley in 1981 and Abel and Blanchard in 1983. His study on the stimulating effects of accelerated depreciation and the various components of capital income taxation on intertemporal, international, and intersectoral allocation is still considered one of the standard works in this field. Sinn contributed to the discussion on German pension reform with his article "Pension Reform and Demographic Crisis. Why a Funded System is Needed and Why it is Not Needed" published in 2000. Here, with the help of present-value equivalents, he showed that the low returns from statutory pension insurance based on the pay-as-you-go method has only an apparent efficiency disadvantage in comparison to a capitally funded procedure. This finding was further developed in a number of subsequent studies. Recently Sinn has turned to the problem of the global warming in an article "Public Policies against Global Warming" and in his book "Das grüne Paradoxon" (the English version, The Green Paradox, was published by MIT Press in 2012). In these studies Sinn developed a supply-side theory of climate change by linking climate-theory approaches with the theory of exhaustible natural resources. His "green paradox" states that environmental policies that promote substitute technologies over time with increasing intensity (and in the process lower the prices for fossil fuels relative to the values they otherwise would have obtained) will induce the resource suppliers to accelerate extraction, thus contributing to global warming. Economic policy positions In 2005 he was one of the first German economists to sign the "Hamburger Appell", which argued for fundamental supply-side reforms and rejected demand-oriented concepts of economic policy. At the same time Sinn employs the instruments of Keynesian demand theory for his analyses of economic activity. With his studies on pension insurance, in which he argued for partial capital funding, as well as by providing direct advice to the Federal Ministry of Labour and Social Affairs (through CES, his university institute) and by contributing to an expertise on pensions for the Ministry of Economics, Sinn had a hand in the introduction of the "Riester-Rente", a privately financed pension scheme support by the German government in the form of grants and tax deductions. In 2003 he