Corporate groups are notoriously difficult to tax. At the moment it is not clear whether corporate groups should be approached as single taxable entities, or whether a separate tax existence should be attributed to corporate group members. The current ambiguity generates a substantial deadweight loss. This study determines what may be the best approach to tax corporate groups, once the perspectives of government and corporate groups are taken into account. The study adopts an interdisciplinary approach, whereby elements, such as market imperfections, the economic, legal and functional nature of corporate groups and the rules of related regulatory fields, are brought into the investigation. The study is based on the US federal corporate income tax system, although, for certain issues, the UK tax system is analyzed. The study adopts a closed economy perspective. The study shows that the design and operation of the corporate income tax system is subject to several constraints and distortions, and argues that to simply look at how far a certain policy is from optimality may be insufficient to determine whether an incremental improvement occurs. The study proposes a new approach to corporate income tax policy whereby the pursuit of incremental improvements requires the minimization of transaction costs and other sources of deadweight loss and the taking into account of the collateral effects of the corporate income tax system, including its interaction with market imperfections, the behavioural and operational nature of business entities, the frictions imposed by other regulatory fields and corporate governance. Following this policy approach, the study concludes that treating corporate groups as single taxable entities is the best approach to tax corporate groups and recommends a revision of certain technical aspects of the current US and UK legislation for taxation of corporate groups.

The recession that started in the late 2000s has created significant economic and financial challenges globally and within nation states. In particular, oil-producing countries have been further affected by the fall in oil price. It is therefore crucial that alternative, more sustainable methods of sourcing revenue be investigated and utilised. The purpose of this thesis therefore is to examine the use of corporate tax regimes as a sustainable revenue source in promoting economic growth and development in Nigeria. Using a qualitative legal analysis, of the Nigerian corporate tax regime and through an extensive literature review, the thesis identified a number of key findings. Inter alia, that revenue from corporation tax structures are a sustainable revenue source mostly because of the amount of revenue generated through Multinational Corporations (MNCs). Secondly, the existing Nigerian corporation tax regime is in need of reform as there are developmental challenges, including lack of implementation and ambiguous legislation, which continue to thwart its success. Therefore, this leads to establishing how, and to what extent that Nigeria can use its corporate tax regime as a sustainable revenue source. The answer to this lies in the legal framework of corporate tax regimes. This thesis argues that legal uncertainties in the corporate tax regimes are the principal reason for the challenges faced by both state governments and MNCs. The thesis concludes by recommending reforms to the Nigerian tax regime while also recommending a tax compliance strategy for both domestic and international corporate tax regimes. This will set a foundation for corporation tax regimes as a sustainable revenue generation source for developing countries.