本論文では日本の企業組織再編税制について、その特徴や問題点を明らかにするとともに、企業組織形態の選択に及ぼす影響について分析を行っている。その意義は，企業における組織再編時の税務計画策定の参考となること、さらには今後の税制改正に向けた政策的指針を提示することにある。本論文の結論として次の３点を示す。
（１）共同事業要件の存在により，合併の多くが税制適格となり、被合併法人の未処理欠損金などの税務属性を引き継ぐ。その欠損金の利用について、日本では米国ＩＲＣ382条のような制限規定がないため租税便益の現在価値は相対的に大きくなる。
（２）単独分割型分割は支配株主がいない場合には税制適格とならないため、事業分離による企業価値増大が阻害される。
（３）そこで、企業では中間型分割を利用するなどの工夫が必要となるが、政策的には会社分割の税制適格要件を見直し、合併と分割における課税上の非対称性・不可逆性を解消し、より機動的かつ柔軟な組織再編を担保する必要がある。
A Study of Tax Issues Associated with Corporate Reorganizations in Japan
The purpose of this study is to examine the effects of Japan's new taxation of corporate reorganizations on corporate restructurings. In the recent 2001 tax reform, significant changes were made to the tax code in connection with corporate reorganizations such as mergers, corporate divisions, investment in kind, and post establishment transfers.
Firstly, after the reform, the acquiring firm may, in principle, assume the accumulated losses from the target firm in the case of a qualified merger. Additionally, there are not such postacquisition limitations based on ownership changes as in the U.S.(IRC Section 382), that the present value of tax benefits from the assumption of losses might be large relatively.
Secondarily, according to the new tax provisions on corporate divestitures, tax-free spin-off cannot be carried out if no one holds the majority shares of the divesting firm, except for the case of a joint enterprise. Spin-off is a dominant divestiture method which can break up the entity into a completely independent company, thereby dissolving the conglomerate discount. But, listed companies do not have any majority shareholders generally; therefore Japanese firms cannot take advantage of the tax-free spin-off for the divestitures.
The results presented in this study indicate that the Japanese tax provisions give many incentives to promote amalgamation, especially mergers with deficit subsidiaries, and lead to the stagnation of corporate divisions, which will miss a chance to improve the competitiveness and the enterprise value. Consequently, as an appropriate strategy for this problem, an eclectic divestment is proposed in which the majority shares of the new entity are distributed to the divesting corporation, and the remainder is distributed to the shareholders.
From a tax policy perspective, the results also suggest that the qualification requirements for tax-free treatment should be amended to promote spin-off, which may dissolve the asymmetric tax treatment between mergers and divisions.
Further research includes the empirical analysis such as a case study to verify the tentative theories. It is important to accumulate the research findings for future tax reforms and corporate tax planning.