各種のデータに対して、なんらかの基準を用いていくつかのグループに分ける分類は、
多くの分野において古くから行われてきた。しかし、時間や空間の広がりの中で観測さ
れるデータに対する分類については、時間や地域に対するデータの集積性の観点から分
類を行う方法以外、時空間全体を分類する手法はあまり提供されていない。本講演では、
時間的・空間的に得られるデータに対して、エシェロン階層情報に基づき時空間データ
や領域の分割及び分類する方法を説明する。さらに、各種統計量の確率分布の計算方法
及び時空間上での集積性や複雑性に関わる新手法とその応用について紹介する。

【応用ミクロ経済学・産業経済学ワークショップと共催】

要旨：This paper provides a theory of the location of firms and, as cities are groups of firms, the emergence of cities. Using a model of equilibrium entry, this paper provides a microfoundation for central place theory and the conditions under which Zipf’s law for cities emerges. Central place theory describes how a hierarchical city system with different layers of cities serving different sized market areas forms from a uniformly populated space. Zipf’s law for cities, that is, the size distribution of cities following the Pareto distribution with a tail index close to 1, is a robust empirical regularity. In the model, the main force driving the size difference of cities is the tradeoff between transportation cost and scale economies, which differs across goods due to different fixed costs of production. Since a central place hierarchy also implies a hierarchy of firms, Zipf’s law for firms is also approximated. The theory is also consistent with a newly discovered empirical regularity, the number-average-size rule, which is a log-linear relationship between the number of cities and the average size of cities where an industry is located.

要旨：Both the term “regional economic integration” and that the economics of integration developed as a sub-branch of international economics are used lavishly in the case of domestic inter-regional analysis in China currently on one hand. While the new economic geography developed as a framework of spatial analysis is flooding the classrooms of economics at major universities in mainland China, on the other hand. Based on the analysis of the peculiarities of the multi-layered regions and deep governmental involvements in both national economy and regional ones extensively, this paper suggests that a clever choice is to combine the both instruments together in analyzing the inter-regional economic relationship of the Chinese economy, considering its complexities and peculiarities being an economy both in the process of institutional transition and industrialization.

要旨：We criticize the theories used to explain the size distribution of cities. They take an empirical fact and work backward to obtain assumptions on primitives. The induced theoretical assumptions on consumer behavior, particularly about their inability to insure against the city-level productivity shocks in the model, are untenable. With either self insurance or insurance markets, and either an arbitrarily small cost of moving or the assumption that consumers do not perfectly observe the shocks to firms' technologies, the agents will never move. Even without these frictions, our analysis yields another equilibrium with insurance where consumers never move. Thus, insurance is a substitute for movement. We propose an alternative class of models, involving extreme risk against which consumers will not insure. Instead, they will move, generating a Frechet distribution of city sizes that is empirically competitive with other models.

【応用ミクロ経済学・産業経済学ワークショップと共催】