Examination of the "E-Commerce Business Transformation" of Local Governments and Distortions in Fiscal Structure Caused by the Furusato Nozei System

Abstract This study conducts an empirical analysis of the changes brought about by the Furusato Nozei (Hometown Tax Donation) system on the fiscal structure and administrative functions of local governments. The analysis focuses on financial settlement data from FY2019 to FY2024 (Reiwa 1 to Reiwa 6) for four characteristic cities in Chiba Prefecture: Katsuura, Urayasu, Minamiboso, and Ichikawa. The results reveal a reality where fiscal stability is undermined in certain municipalities due to drastic fluctuations in donation revenues. Furthermore, the study confirms a high-cost structure where approximately 50% of received donations flow out externally as expenses, as well as a "coercive force of the system" that compels even wealthy municipalities—which originally had no need to compete—to participate defensively. This paper points out the current status of municipalities transforming from providers of public services into "specialty product retailers (EC operators)" and examines the sustainability of the system. 要旨 (Japanese Abstract) 本研究は、ふるさと納税制度が地方自治体の財政構造と行政機能に与える変容について、千葉県内の特徴的な4市(勝浦市、浦安市、南房総市、市川市)の令和元年度から令和6年度までの決算データを基に実証的な分析を行うものである。分析の結果、一部の自治体では寄付受入額の急激な乱高下が見られ、財政の安定性が損なわれている実態が明らかとなった。また、受入額の約50%が経費として外部流出する高コスト構造や、本来競争に参加する必要のない富裕自治体までもが防衛的に参戦せざるを得ない「制度の強制力」が確認された。本稿では、自治体が住民サービス提供機関から「特産品販売業者(EC事業者)」へと変質しつつある現状を指摘し、制度の持続可能性について考察する。