合併市町村における歳入規模と地方交付税水準の肥大化の検証 <論文>

2002年度からのほぼ10年間で、わが国の市町村数は3,212から1,719に減少した。この間、「三位一体の改革」によって地方への税源移譲と地方交付税・国庫支出金の削減が進められる一方、市町村合併の促進を目的として、地方交付税の「合併算定替」と合併特例債の発行が認められたことにより、合併市町村では歳入が肥大化した。本稿では、非合併市町村を対象に、人口と面積から歳入規模を推計し、基準財政需要額/基準財政収入額比率から人口1人あたり普通交付税の水準を推計した。これをベンチマークとして合併市町村に適用し、推計値と実績値の乖離状況を点検した。その結果、構成市町村数が多く中心都市占有率が低い市町村は、そうでない市町村に比較して歳入規模と普通交付税の水準が高いことなどが明らかにされた。合併市町村全体における歳入の超過幅は約2.5兆円、普通交付税のそれは約1.1兆円と見込まれる。合併 市町村では、まもなく地方交付税の段階的縮減や合併特例債の償還が始まるため、実態を認識して、早めの対応を図っていく必要がある。

The reform of local public finance was carried out along with the merger of municipalities in early 2000's. The tax revenue resources were devolved from the central government into the local ones, while the national treasury disbursement and local allocation tax were reduced. At the same time some special measures have been allowed to accelerate the merger. It has resulted in consequences that revenue of the merger experienced municipalities has swollen.

We estimate the desirable level of revenue and local allocation tax from the data of the merger non- experienced municipalities by population scale. With applying them into the merger experienced ones by scale, we assess the degree of swelling in the revenue and local allocation tax.

As the result we can see that the more the number of composed cities and towns before the merger and the less the share of the most populated city among them, the more the revenue and local allocation tax per capita of the merger experienced municipalities. The excess of revenue amounts to \2.5 trillion and local allocation tax \1.1 trillion. The moratorium placed by the special measures promoting the merger will finish in the next several years. The merger experienced municipalities must orient themselves toward the similar level of public finance management as the merger non-experienced ones as soon as possible.