From June 15 to June 19, 2026, Floris Tobias Zoutman (NHH – Norwegian School of Economics) visited the Institute of Public Finance. During his stay, he taught a master's seminar on “Household Finance and the Tax System” as an Adjunct Professor at Leibniz University Hannover, exchanged ideas with faculty members and researchers on current research topics, and presented a recent research project as part of the Institute’s Research Seminar.
In his presentation, “Redesigning the Dividend Withholding Tax: Closing Loopholes and Strengthening Enforcement,” he discussed how European governments can better protect their Dividend Withholding Tax (DWT) base against tax-motivated trading around ex-dividend dates. Using securities-lending data, he demonstrated how cum-cum, cum-ex, and related dividend-arbitrage strategies can be analyzed across European capital markets and how changes in lending activity around ex-dividend dates can be used to evaluate the effectiveness of enforcement reforms. Drawing on evidence from several European countries, including Germany and Denmark, the presentation showed that spikes in securities lending around dividend dates provide a useful measure of dividend-arbitrage activity.
