DE / EN
Johannes Gaul, M.Sc.

Johannes Gaul, M.Sc.

E-Mail:           johannes.gaulmail-uni-mannheim.de

Phone:           +49 (0) 621 – 1235 169

Adress:           Universität Mannheim
                          Schloss Ostflügel
                          68131 Mannheim


  • Teaching

    Bachelor:

    Master:

    • Seminar- und Masterarbeiten

    Mannheim Master Accounting and Taxation:

    • Seminar- und Masterarbeiten
  • Research Interests

    • Real Effects of Taxation
    • Political Economy
  • Publications

  • Projects

    BAK Taxation Index 2024/2025

    In the context of a growing international economic integration, taxation becomes a more and more central factor in the competition of regions and countries for international investment and skilled employees. From that perspective, in addition to the effective level of company taxation also the effective tax burden on highly skilled employees is important: Due to the growing international mobility of highly skilled employees, these employees compare net incomes and force companies to bear international and interregional differences in compensation tax burdens. The present research project will analyze effective tax burdens on corporations and on highly skilled employees in Switzerland for 2024. Additionally, it will analyze the effective tax burden in more than 50 different locations from 19 European countries, the U.S. and Asia for 2025. Thereby, it will update and analytically extend the BAK Taxation Index, which has been published first in 2001. In addition, the implications of the global minimum tax in Switzerland will be analyzed.

    The Provision of Effective Tax Rates and Related Supporting Services – Backward-looking Effective Tax Rates

    In its Communication on Business Taxation in the 21st Century, the European Commission emphasises the need for a sound, efficient and fair tax framework that meets public financing needs while supporting recovery, sustainable growth and investment. In this context, corporate tax systems and their complexity play an important role in the investment decisions of domestic and foreign companies.

    Given the rapid pace of change in taxation, it is important to have the tools and data to analyse the evolution of corporate tax systems and their impact on business decisions. Comparable time series data on the evolution of effective tax burdens are essential as they can inform the policy debate on the impact of corporate taxation. In addition, the data allow the analysis of potential distortions from taxation.

    The decision effects of taxation always refer to the future tax burden associated with a particular business decision. Forward-looking tax rates reflect the decision-related tax burden and are therefore best suited for analysing the decision and incentive effects of corporate taxation. In contrast, backward-looking tax rates are always based on empirically observed data, i.e. they do not capture the incentive effects of tax provisions, but reflect the tax consequences of actual business decisions (including tax optimisation and the use of tax incentives). Backward-looking effective tax rates can be derived from company data (unconsolidated or consolidated accounts) or from macroeconomic data.

    The project includes a comprehensive review of the literature on backward-looking effective tax rates, the joint development of a common methodology for calculating backward-looking indicators of the effective level of corporate taxation with the EU Commission and the OECD, and the creation of a database of backward-looking effective tax rates, complemented by detailed annual reports.

    BAK Taxation Index 2022/2023

    In the context of a growing international economic integration, taxation becomes a more and more central factor in the competition of regions and countries for international investment and skilled employees. From that perspective, in addition to the effective level of company taxation also the effective tax burden on highly skilled employees is important: Due to the growing international mobility of highly skilled employees, these employees compare net incomes and force companies to bear international and interregional differences in compensation tax burdens. The present research project will analyze effective tax burdens on corporations and on highly skilled employees in Switzerland for 2022. Additionally, it will analyze the effective tax burden in more than 50 different locations from 19 European countries, the U.S. and Asia for 2023. Thereby, it will update and analytically extend the BAK Taxation Index, which has been published first in 2001. In addition, the implications of the global minimum taxation in Switzerland (STAF) will be analyzed.

  • Talks

    • 2023: Tax reforms – triggers and effects, Budget and Finance Days 2023, German University of Administrative Sciences, Speyer, Germany
    • 2024: Development potentials of the data infrastructure for analyzing tax measures using the example of DAC7, Annual Conference – Network for Empirical Tax Research, Berlin, Germany
    • 2024: Panel NeSt – Network Empirical Tax Research of the BMF, Annual Conference Association for Social Policy (VfS), Berlin, Germany