The tax system provides an essential legal framework for the behavior of public and private actors, in particular of private businesses. It ensures the funding of state activities and sets incentives for private entities at the same time. A comprehensive legal analysis of tax rules and principles, therefore, has to encompass both private law and public law as well as both corporate and public finance. Against this background, tax research at the Institute is devoted to tax law within the network of civil law, corporate law and accounting law on the one hand, and the constitutional, European and international background on the other hand. The research is focused – apart from fundamental themes like the rule of law in tax matters – on comparative, European and international business taxation, on legal and policy implications of cross-border tax competition and on the mutual dependence of rule-setting in private law and tax law.

Limitations of tax sovereignty
International profit allocation
Debt, Equity and hybrid financial instruments
Tax law and corporate law as competitive factors
Internationalisation of accounting

Accounting lies at the interface of different areas of business law and serves a variety of different purposes. For the owner of a business as well as for potential investors, the balance sheet is an important source of information; additionally, for corporations, it is used to identify the profit that may be distributed to shareholders and therefore serves the creditor’s interest. Finally, it is also relevant for tax purposes, as in many countries the financial balance sheet is the starting point for determining a company’s taxable profit. Against the background of these multiple purposes of accounting, the Institute’s research addresses basic questions and specific issues. Furthermore, we analyze the conflict between business disclosure rules and legitimate concerns of secrecy.

Internationalisation of accounting
Debt, Equity and hybrid financial instruments

Corporate law consists of the two parts corporate governance and corporate finance. As soon as a company approaches the public capital markets, it is also subject to securities regulation. While corporate law is concerned with the rights and duties of shareholders and corporate bodies within the corporation, secu-rities regulation aims at protecting investors as well as the functioning of the market. Corporate and capital markets research at the Institute departs from the competition of legislators, which has been sparked decisively by European law. Research at the Institute is therefore first and foremost devoted to the European foundations as well as to comparative and economic analysis of corporate law and securities regulation. Furthermore, corporate law and securities regulation are both closely intertwined with accounting and tax law: Corporate and capital markets law obliges companies to prepare and publish annual accounts as well as interim reports and the like. Corporate organization, especially the choice of corporate form, has important fiscal effects for the company as well as its shareholders. Against this background, the Institute’s legal research in corporate and capital markets law strives to combine international business reality with legal doctrine as well as economic theory. This requires a functional approach, which relies on internationality as well as interdisciplinarity.

Debt, Equity and hybrid financial instruments
Tax law and corporate law as competitive factors
European Corporate law
Legal rules for closed corporations

Research at the Institute does not focus on private law in isolation but rather within the overall framework for private, in particular business behavior. This brings about questions of legal doctrine and legal policy which have to be assessed in the context of other legal fields as well. A topic of paramount theoretical and practical importance is the interaction between private law and public law as it is well known from the interdependence between freedom of contract on the one hand and tax legislation on the other hand. A policy-oriented research topic is the alternative between private law statutes and public law rules when it comes to optimal steering of market processes. Moreover, substantive elements of the private legal order are examined, e. g. the relevance of the “information model” as opposed to mandatory requirements. A further-reaching perspective encompasses the European framework emerging from current work on a pan-European private law.