How to adapt international tax arrangements to a new global environment? How should enterprises that operate in different countries be taxed? Can tax systems be simple, fair and effectively administered? Policymakers are looking to tax systems to help solve social and economic problems. Responding to these challenges and shaping the tax system of the 21st century are issues addressed by the OECD.

The OECD's Centre for Tax Policy and Administration is at the forefront of setting international tax standards, such as the OECD Model Tax Convention and the Transfer Pricing Guidelines. It is regularly involved in resolving politically sensitive issues, which include non-OECD economies, such as in the harmful tax competition project.

The OECD also monitors the fiscal policies of its member countries, which enables macroeconomic projections. In the context of the Economic Surveys, the OECD has reviewed in detail the tax systems of a large number of countries. This in-depth analysis provides national authorities with options for reforming the tax system so as to improve efficiency, equity and enforceability.

A cross-country synthesis survey has been published, pulling together the country-specific work. It presents the main challenges facing tax policy makers and provides policy recommendations. These surveys are available as ECO Working Papers. Major work has also been done in whether there is scope to use taxes to help produce a cleaner environment  and encourage sustainable development.