تحلیل خط مشی زیست محیطی: رویکرد محاسبه زیست محیطی تعادل عمومی برای کشورهای در حال توسعه

Environmental pollution is now a serious problem in many developing countries. One approach to combat the problem is to implement various pollution control policies. However, due to a lack of adequate quantitative models, the economic impacts and effectiveness of many pollution control policies are still unknown. This article uses the computable general-equilibrium (CGE) approach to develop an integrated economic and environmental model for environmental policy analysis for developing countries. The model presented here incorporates various environmental components, including pollution taxes, subsidies, and cleaning activities, into a standard CGE framework. The study also presents an environmentally extended social accounting matrix (ESAM), which serves as a consistent data set for calibrating the model. The model is applied to China, the largest developing country in the world, for evaluating the effectiveness of Chinese environmental policies on pollution control and their impacts on the Chinese economy. The environmental policies under scrutiny include pollution emission taxes and pollution abatement subsidies. The economic impacts of the waste water treatment plan in China's recently launched five-year environmental protection program are also examined.

Environmental problems are serious and pervasive in today's world. In many developing countries, industrial pollution emissions continue to increase and, as a result, environmental problems, such as deforestation, soil erosion, and the expansion of desert areas, are aggravated. These problems have severely threatened the sustainable development of these countries and have caused great concern at all levels, from the general public to national governments and international agencies. Because they face serious environmental degradation, the governments of many developing countries have begun to introduce environmental policies and regulations to combat environmental problems. The most popular environmental policies include pollution taxes, environmental impact assessments, pollution subsidies, and pollution emission permits. However, due to a lack of adequate quantitative models for environmental policy analysis, the effectiveness of pollution controls and the economic impacts of these policies are still unknown. Therefore, there is a strong need for analytical models for environmental policy analysis. The computable general-equilibrium (CGE) approach is adopted for environmental policy modeling in this research. Compared with other modeling techniques, such as the input–output approach and linear programming, the CGE approach has appealing features for modeling environmental policy analysis. The four major features of a typical CGE model are listed as follows. First, prices are endogenous to the model and are determined by the “market.” Second, the model focuses on an economy where supply and demand for either goods or production factors are equated by adjusting prices based on Walrasian general-equilibrium theory. Third, supply and demand functions in the model are derived from the behavior of profit-maximizing producers and utility-maximizing consumers. Finally, a CGE model is usually multi-sectoral and non-linear, and contains resource constraint. In the late 1980s, the CGE approach began to be applied to environmental issues. Even though many of these applications still are in experimental stages, they show that the CGE approach has advantages for environmental policy modeling. This article consists of six sections. Following this introductory section, Section 2 reviews the literature in environmental CGE models. Section 3 develops an environmental CGE model. It begins with an introduction to the interactions between production and pollution. The theoretical framework of a multi-sector environmental CGE model is then developed in this section. Section 4 introduces the framework of an environmentally extended social accounting matrix (ESAM). The ESAM serves as a consistent equilibrium data set for parameter calibration of the environmental CGE model. The application of the environmental CGE model to China using 1990 Chinese data is presented in Sections 5. Several Chinese environmental policy alternatives are simulated in this section, and the major findings from these policy simulations are discussed. Section 6 contains concluding remarks.

Further study of this topic can take, at least, two directions: improving the model and applying the model to a broader spectrum of policy analyses. The model can be refined in several respects. For example, the demand of a production sector for pollution abatement services is currently specified in a simplified way. It uses average pollution cleanup rates and assumes that the unit costs for pollution abatement are independent of the cleanup rates. With more exploration in the economics of pollution abatement, the demand function can be more accurately defined, and the cleanup rates can be made sectorally specific. These modifications will bring the model closer to the real world case. Applications of the environmental CGE model for policy analysis are not limited to the few policies presented in the previous chapter. As noted earlier, the current pollution levy system in China is ineffective in reducing pollution emissions. It has been observed that this ineffectiveness is caused not only by low effluent fees but also by weak legal enforcement of pollution emission taxation. Therefore, there is room to reduce pollution emissions by strengthening enforcement of pollution emission tax collection. The pollution emission tax equation includes an implementation adjustment factor to capture the difference between the planned pollution emission taxes and the actually collected pollution emission taxes. By increasing the implementation factor, one can examine the outcomes of enhancing the legal enforcement of pollution emission taxes on the economy and on pollution control. Upgrading equipment and production technology is a very effective approach in reducing pollution generation and emissions. Like other countries, China has paid great attention to importing advanced and less-polluting technology from abroad to increase productivity and reduce pollution intensities. The economic and environmental impact of technological improvement can be assessed by changing the relevant technical coefficients such as the input-output coefficients and the pollution intensity coefficients in the model. Although the application of the model focused on environmental policy analyses, the model is also useful for analyzing the environmental impacts of an economic policy. For example, the Chinese government is planning to further increase coal production and to develop a family car industry. With an appropriate sector classification, the model could be used to assess the impacts of these policies on China's environment. Ahmad El Serafy Lutz 1989, Bartelmus Stahmer van Tongeren 1993, Bergman Jorgenson Zalai 1990, Bergman 1990, Bergman 1991, Forsund Hoel Longva 1985, Johansen 1974, Keuning 1993, Leontief 1970, Lutz 1993, Taylor 1979, Taylor 1990, United Nations. 1993 and Wang 1994