A better understanding of what motivates taxpayers to participate in and comply with a tax system is valuable for all countries and stakeholders. Tax administrations can benefit from increased compliance and higher revenues, taxpayers (both businesses and individuals) are better served by tax systems that understand and are responsive to their needs, while increased data and discussion can help researchers deepen their understanding. In addition, such understanding can help organizations improve their communication on taxation and development partners to maximize the impact of development assistance.