The paper looks at the changes that have taken place in the way researchers examine the influence of taxes on economic growth and competitiveness, both in Poland and elsewhere. These changes have primarily involved a broader look at this issue over the past decade or so, the author says. For decades in the past, researchers focused on analyzing the direct influence of taxes on economic growth. With time, they expanded their approach to include various aspects of taxation and types of taxes. They began to separately examine the impact of personal income tax, corporate income tax and indirect taxes, looking at their average, minimum and maximum effects through the lens of supply-side economics. Supply-side economics is an economic theory that states that a reduction in taxes stimulates the economy enough to recoup the lost revenue. Today those researching the impact of taxes on economic growth and competitiveness increasingly acknowledge that the influence of taxes on an economy depends on the context in which tax policy is pursued, Wnorowski says. This particularly applies to institutional conditions in which taxes are levied and modified. Of special importance are any legislative difficulties or limitations encountered by tax policymakers, the overall thrust of government policy, and the efficiency of authorities responsible for the enforcement of tax regulations and laws, according to the author. Wnorowski analyzes research reports on the subject and he also takes a look at expert studies by international institutions such as the World Bank and Organization for Economic Cooperation and Development (OECD). Such studies have abounded in the last few years, highlighting the role of various institutional factors, according to Wnorowski. When analyzed collectively, institutional factors make it possible to better understand the relationship between taxes and economic growth as well as changes in the level of competitiveness. Overall, an institutional economic approach is now increasingly common in research into the influence of taxes on economic growth, the author says.