We study the relationship between tax progressivity and the size of the R&D workforce, using a panel of European countries in 2000-2019. We review the theoretical literature which provides opposing predictions about such a relationship. We then demonstrate that such relationship exists as a "within" effect, it is negative, meaning that a larger tax progressivity is associated with smaller shares of employment in R&D activities, and it remains statistically significant after performing a number of robustness tests. Differently to previous studies based on patenting inventors, we find no effect due to top tax rates on the size of R&D employment
