Indirect Tax Competition and Harmonization in Europe

本项目的目的是研究欧洲实际销售税的竞争与协调，这是欧洲最重要的经济问题之一。通过对列支敦士登公国、瑞士和奥地利等欧洲国家的调查，我们可以用纳什博弈均衡来构建更现实、更本质的模型。为此，我们明确考虑了流动性、跨境购物者、地理变量（如国家大小和位置）以及欧盟（欧盟）的税收政策。今年，为了关注全球范围内的流动扩展，我们从实证和理论两方面考察了国家规模和地理位置对税率和税收收入的影响。本文考察了一些欧洲内陆小国，构建了简单的纳什均衡模型。首先，我们考察了被经济合作与发展组织（OECD）视为税收天堂的列支敦士登公国的实际税收竞争和协调。其次，除了空间税收竞争模型外，我们还对国际上关于无空间税收竞争模型的论文进行了综述。第三，我们使用Voronoi图来模拟二维空间中的税收竞争，Voronoi图是计算几何中的基本工具。此外，我们在网络中开发了该模型，并将其应用于引入权力下放后的日本税收竞争。最后，我们将部分结果发表在日本的一本书中，即日本建筑学会编辑的《建筑优化导论》。

The purpose of this project is to investigate the actual sales tax competition and harmonization in Europe, which is one of the most important economic problems in Europe. Based on the investigation in European countries such as Principality of Liechtenstein, Switzerland and Austria, we can formulate more realistic and more essential model using Nash game equilibrium. For this, we explicitly take account of mobility, cross-border shoppers, geographical variables such as country sizes and locations, and tax policy of EU (European Union).In this year, in order to focus on the mobility extension in the world, we examine empirically and theoretically how the country size and location affect the tax rates and tax revenues. We visit some European small and interior countries and construct simple Nash equilibrium models. First, we examine the actual tax competition and harmonization in Principality of Liechtenstein which is regarded as tax heaven by OECD (Organization for Economic Cooperation and Development). Second, we survey the international papers on spaceless tax competition models in addition to spatial tax competition models. Third, we model tax competition in two-dimensional space using Voronoi diagrams which is fundamental tool in computational geometry. Also, we develop the model in the network and apply it to Japanese tax competition after introducing decentralization of authority. Finally, we publish partially our result in Japanese book, i.e., Introduction to Optimization in Architecture, edited by Architectural Institute of Japan.