Comparative Institutional Analysis of Local Government Bonds

本稿では，我が国の地方債制度と市場指向型のアメリカの地方債制度を，理論的に経済厚生の比較分析を試みた．我が国の現行の地方債をめぐる制度は，起債許可だけでなく，財源の使途や貸し手も予め定める地方債許可制度，地方交付税を通じた地方債元利償還金の後年度負担（措置），自治体の決済資金不足に備えた地方財政再建制度が，制度補完的に構築されている点が特徴である．この制度の下では，自治体間に信用力格差があっても地方債利子率には反映せず，地方交付税の財源である国税の納税者にリスクを負担させている性質が強い．他方，アメリカの制度では，自治体の信用力は格付等によって情報が市場参加者の間で共有され，市場における金利形成を通じて，地方債が発行されている．この下では，市場参加者（債務者・債権者）の間でより広くリスクを負担する性質が強い．これらの性質を，両国の地方債制度を紹介するとともに，定性的に理論分析を行い，わが国の地方債制度の改善点を明らかにした．We model economic institutions behind Japanese local government bond issues. We also model the more market-oriented system behind U. S. local government bond and draw welfare implications from the comparison of Japanese and U. S. systems. Japanese system requires the permission of issuing from the central government which determines the use of funds raised by local government bond issue and who should buy those bonds. (Ex post) subsides for interest and debt payment as well as the mechanism for the reconstruction of local government budget in the case of (near) default also characterize the Japanese system. Under such heavy protection by the central government, bond yields do not reflect credit risk of local government and therefore ex post burden is transferred to national, not local, tax payers. On the other hand, U. S. system make credit risk to be reflected in local government yields because of rating and other market oriented mechanism, so that risk are shared by market participants. Implications for improvement of the Japanese system are presented and discussed toward the end of the paper