Fujiwara Yoshi, Inoue Hiroyasu, Yamaguchi Takayuki, Aoyama Hideaki, Tanaka Takuma, Kikuchi Kentaro
Graduate School of Information Science, University of Hyogo, 650-0047 Kobe, Japan.
The Center for Data Science Education and Research, Shiga University, 522-8522 Hikone, Japan.
EPJ Data Sci. 2021;10(1):19. doi: 10.1140/epjds/s13688-021-00274-x. Epub 2021 Apr 21.
In this study, we investigate the flow of money among bank accounts possessed by firms in a region by employing an exhaustive list of all the bank transfers in a regional bank in Japan, to clarify how the network of money flow is related to the economic activities of the firms. The network statistics and structures are examined and shown to be similar to those of a nationwide production network. Specifically, the bowtie analysis indicates what we refer to as a "walnut" structure with core and upstream/downstream components. To quantify the location of an individual account in the network, we used the Hodge decomposition method and found that the Hodge potential of the account has a significant correlation to its position in the bowtie structure as well as to its net flow of incoming and outgoing money and links, namely the net demand/supply of individual accounts. In addition, we used non-negative matrix factorization to identify important factors underlying the entire flow of money; it can be interpreted that these factors are associated with regional economic activities. One factor has a feature whereby the remittance source is localized to the largest city in the region, while the destination is scattered. The other factors correspond to the economic activities specific to different local places. This study serves as a basis for further investigation on the relationship between money flow and economic activities of firms.
在本研究中，我们通过使用日本一家地区银行所有银行转账的详尽清单，调查该地区企业所拥有银行账户之间的资金流动，以阐明资金流动网络与企业经济活动之间的关系。我们对网络统计数据和结构进行了检验，结果表明它们与全国生产网络的统计数据和结构相似。具体而言，蝴蝶结分析表明了一种我们称之为具有核心以及上游/下游组成部分的“核桃”结构。为了量化单个账户在网络中的位置，我们使用了霍奇分解方法，发现账户的霍奇势与其在蝴蝶结结构中的位置以及其资金流入和流出及链接的净流量（即单个账户的净需求/供给）具有显著相关性。此外，我们使用非负矩阵分解来识别整个资金流动背后的重要因素；可以解释为这些因素与地区经济活动相关。一个因素的特点是汇款来源集中在该地区最大的城市，而目的地则分散。其他因素对应于不同地方特有的经济活动。本研究为进一步研究资金流动与企业经济活动之间的关系奠定了基础。
