مالیات محیط زیست و اثرات اقتصادی: تجزیه و تحلیل تعادل عمومی قابل محاسبه برای ترکیه

This study explores economic effects of environmental taxation using an energy–economy–environment computable general equilibrium model of the Turkish economy. The model disaggregates the Turkish economy into seven sectors and describes production within a nested CES representation. Results, which are obtained under a Business-As-Usual as well as various environmental tax scenarios, provide insight into energy–economy–environment interactions in Turkey and indicate opportunities for an ecologically and economically sustainable development of the country. Besides general policy implications, it is found that a second dividend of environmental taxation, that is economic benefits in addition to environmental improvements, is possible when imported fuels are the primary source of pollutant emissions. This result has been obtained under tax revenue recycling that assumes public consumption of tax revenues instead of the common practice of using tax revenues for reducing existing tax distortions in order to obtain a second dividend.

Parallel to ongoing industrialization, Turkey’s primary energy needs have increased rapidly at an average annual growth rate of 5.1% over the last 50 years. The per capita energy use still ranks below the world’s average and only 35% of the primary energy consumption in 2001 (78 MTOE) is provided from domestic sources. The energy imports amount to US$ 8.3 billion, some 20% of Turkey’s total imports in 2001. The bill can be expected to increase significantly in the coming years as the Ministry of Energy and Natural Resources forecasts a doubling of the primary energy consumption by 2010, with the domestic share falling to 27%. Increasing energy imports might become an essential burden to the Turkish economy as the country has a persistent current account deficit and relies on foreign exchange inflows to finance her outstanding external debt (which has reached some US$ 114 billion — nearly 78% of GDP — in 2001). Naturally, such implications are vitally important for the success of the IMF-supported structural reform package.1 The Turkish energy sector is undergoing severe structural changes in a restructuring process to establish competitive energy markets, for which the legal and regulatory framework has been established in late 2001. The market opening underway is triggered by the hope to achieve efficiency gains and improve welfare. The prospect for a rapidly developing energy market is attracting private investors, who are naturally primarily concerned about maximizing profits rather than reducing harmful environmental impacts. Clean energy technologies and emission reduction measures are therefore to be promoted by policy-makers if ecological sustainability is desired. This study explores the economic impacts of environmental taxation as a policy instrument to steer the country into a path of sustainable development. Sustainability is likely to be an issue on Turkey’s roadway to the EU where more stringent emission standards are present. The EU has ratified the Kyoto Protocol on Climate Change committing member countries to reduce their greenhouse gas emissions. Turkey’s compliance with the Kyoto requirements will most probably be on the agenda of her accession talks which can be expected to begin by 2005.2 This puts additional emphasis on the importance of the present study highlighting energy–economy–environment interactions in Turkey. Computable general equilibrium (CGE) modeling is the primary analytical tool available for conducting economic analyses of energy and climate policies. Commercial software packages such as GEMPACK (Harrison & Pearson, 1996) or MPSGE (Rutherford, 1995) have taken advantage of recent algorithmic advances triggering the development of large-scale dynamic CGE type of models (Shoven & Whalley, 1992; among others). Such modeling applications in energy and environmental policy planning are various. The models GTAP-E (Burniaux & Truong, 2002), RICE (Nordhaus & Yang, 1996), DREAM (Vennemo, 1997), WARM (Carraro & Galeotti, 1997) and SCREEN (Frei, Haldi, & Sarlos, 2003; Kumbaroğlu & Madlener, 2003) can be mentioned as some outstanding examples. Each model exhibits different originalities, e.g., the GTAP-E model includes a specific treatment of carbon emission trading, WARM decomposes the capital stock into environment-friendly and polluting parts, DREAM defines environment–economy feedback links via a health-induced productivity index as a function of energy consumption, RICE incorporates an environmental damage function and SCREEN integrates a process-oriented energy–environment linear activity analysis framework into a CGE setting. This paper describes the environment–energy–economy model ENVEEM, a dynamic CGE model with particular reference to energy–environment interactions, presents results from the empirical analysis for Turkey and discusses policy implications. ENVEEM has been designed to study long-term consequences of environmental policy decisions on the adoption of energy technologies and on socio-economic indicators. It is calibrated using Turkish data to reveal opportunities for an ecologically and economically sustainable development of the country. The following section summarizes the main features of ENVEEM. Section 3 provides an overview on energy use and pollutant emissions in Turkey, defines different energy and emission tax scenarios considered in the empirical application, presents the results obtained from the scenario analysis, and discusses policy implications. The final section summarizes the relevant findings for policy-making and concludes the study.

The use of the dynamic CGE model ENVEEM has been discussed in this paper, studying the economic implications of environmental tax reforms in Turkey. Interactions of the energy sector with the rest of the economy are elaborated with respect to various energy and emission tax scenarios. Model results yield several policy implications, which are essential for an environmentally and economically sustainable development of the country. The main findings from the scenario analyses highlight the importance of (1) preferring emission taxation as a policy instrument to achieve environmental improvement, (2) substituting oil and gas instead of hardcoal and lignite to reduce pollutant emissions, and (3) reducing energy imports to speed-up economic development. It has been found that the economic burden of not following these policy suggestions might reach considerable levels amounting to nearly 6% of GDP. Model results further indicate that the above policy suggestions inherit a potential to simultaneously improve both environmental quality and economic performance in Turkey. As Turkey possesses considerable coal reserves and negligible oil and gas reserves,5 the above findings (2) and (3) seem to face policy makers with a trade-off between reducing energy imports and substituting oil and gas for solid fuels. The model, however, combines both policies through a reduction in energy use. The consumption of all energy carriers is reduced (along with a general economic shrinkage), with solids declining faster than oil and gas. Hence, the oil and gas/solids ratio increases while imports of oil and gas are declining. Naturally, policy-makers should aim to achieve such a result without curtailing economic growth. These findings emphasize the significance of energy conservation. It is concluded that policy-makers should support policies to improve energy efficiencies, to increase energy savings, and to reduce the demand for energy-intensive activities. The prospects for a double dividend of environmental taxation, i.e., improvement in environmental quality and at the same time better economic performance, are indicated by the NOx emission tax scenarios. This is because NOx emissions originate to a large extent from the consumption of imported fuels, mainly petroleum products. It has been found that NOx emission taxation decreases the oil imports of NOx-intensive sectors thereby increasing the gross production of nonintensive ones as a result of intersectoral substitution — hence GDP increases. These observations underline the important impact of energy imports, essentially petroleum, on the Turkish economy. It is concluded that policy-makers should target a higher domestic share in primary energy consumption. 6 The achievement of environmental benefits together with economic ones brings a new dimension to the discussion of necessary circumstances for obtaining a double dividend, which mainly centers on the use of environmental tax revenues to correct pre-existing inefficiencies of non-environmental taxes (e.g., Böhringer, Pahlke, & Rutherford, 1997; Bovenberg & Goulder, 1997 and Parry & Bento, 2000). The results of this research indicate that a second dividend of environmental taxation yielding economic benefits is possible even when the tax revenues are not recycled to reduce existing tax distortions — provided that imported fuels are the primary source of pollutant emissions. As a final remark, I would like to underline that — as opposed to most EU countries — Turkey is yet in the stage of industrialization with rapidly increasing energy needs of crucial importance for her economic growth. The development of sustainable energy and environmental policies is therefore a challenging task, for which policy-makers need to take assistance from empirical research. Further research is needed towards exploring the double dividend hypothesis under different tax revenue recycling assumptions. A more detailed representation of future energy technologies is required for model refinement. Research is also further necessary for an explicit modeling of uncertainty in energy demand and prices (essentially due to energy market liberalization).