【正文】 em may improve economic ef?ciency and reduce administration costs, rentseeking and fraud activities by industries that lobby for lower rates and zero ratings (Keen and Smith 2020). A general and uniform VAT system equals a uniform consumer tax on all goods and services. Such a system also implies that the producers’ VAT rate on material inputs equals zero, irrespective of the rate structure. This is optimal according to the production ef?ciency theorem (Diamond and Mirrlees 1971a, 1971b).A VAT system with exemptions violates the production ef?ciency theorem because taxation of intermediates will differ between industries. On the other hand, industries that are covered by the VAT system but have lower rates or zero ratings on their sales are favored because they can withdraw expenditures to VAT on intermediates at full rates and only levy reduced or zero rates on their sales. A general and uniform VAT system may also have positive effects on the distribution of welfare among households. If the initial situation is characterized by a VAT on most goods but only on a few services, the introduction of a uniform rate on all goods and services may improve the distribution of welfare because services’ share of consumption increases with ine. Keen (2020) points to the lack of interest in value added taxation from the theoretical secondbest literature in spite of the VAT’s popularity in practical tax policy. As mentioned 山東建筑大學(xué)畢業(yè)論文外文文獻(xiàn)及譯文 3 above, VAT systems are in general not uniform. Theoretical analyses demand relatively simple models and simple tax structures to be analytically practical policies, the structures of the economy and the tax systems are quite plex, and there is a need for detailed numerical models in order to analyze the effects of different VAT systems. This paper contributes to the literature by analyzing the welfare effects of an imperfect extension of a nonuniform VAT system, and paring different imperfect, nonuniform VAT systems with a uniform and general VAT system within an empirically based dynamic putable general equilibrium (CGE) model for a small open economy. This model mirrors a real economy, Norway, and differs in many respects from the more simple theoretical models that ful?ll the assumptions of normative tax theory and remend uniform modity taxes, bined with no input taxation. In our analyses, we ask the following questions. Can the introduction of a nonuniform VAT system including only some services make the economy worse off than having a VAT system only covering goods and in that case, why? Such reforms characterize both the Norwegian VAT reform of 2020 and the EU VAT reform from the late 1990ties. Will an additional extension to a uniform and general VAT system be welfare superior to the nonuniform (and nongeneral) VAT systems and what are important preconditions? As will be explained below, one cannot on purely theoretical grounds establish the welfare rankings of such VAT systems when there are preexisting distortions as tax wedges and market power in the economy. The baseline VAT system is a nonuniform VAT system mainly covering goods. This baseline VAT system is then pared with (1) the extended nonuniform Norwegian VAT reform of 2020, and (2) a general VAT system characterized by a uniform VAT rate on all goods and services, including public goods and services. The Norwegian VAT reform of 2020 was a step in the direction of a general VAT system by including many services, but there are still many exemptions, zero ratings and lower rates. In particular, the VAT rate on food and nonalcoholic beverages is half the general VAT rate. The policy reforms are made public revenue neutral, and changes in lump sum transfers as well as in the system speci?c VAT rate are studied. With a revenueneutral change in the systemspeci?c VAT rate, the VAT systems can be ranked with respect to welfare effects. Ballard et al. (1987) and Gottfried and Wiegard (1991) analyze the welfare effects of different VAT systems including tax exemptions and zero ratings in static CGE models. The separability and homogeneity assumptions in their consumer demand models favor a uniform VAT system, which is supported in their policy simulations. In contrast, our model is an intertemporal CGE model for a small open economy without strict homogeneity assumptions in consumer demand. Our model is well designed for analyzing VAT reforms because it 山東建筑大學(xué)畢業(yè)論文外文文獻(xiàn)及譯文 4 distinguishes between many industries, input factors and consumer goods and services. The modeling and parameters in the consumer demand system and the production technology are all the results of prehensive micro and macroeconometric analyses of Norwegian data. The model has a detailed description of the Norwegian system of direct and indirect taxes. Speci?cally