Patent box schemes received much critical attention because they allow intellectual property (IP) profits to be taxed at a low or even zero corporate tax rate without a clear link between the R&D activity and the incentive received. Thus, the intention of such schemes did not seem to be exclusively to encourage new R&D activity, but also to attract IP revenues from abroad.   The OECD's recent measures aim to prevent exactly this behaviour: excessive tax planning without the underlying economic activity for the mere purpose of reducing the overall tax burden. Since patent boxes have been legitimised with the Modified Nexus Approach, they remain as an interesting instrument to increase the attractiveness of countries for R&D investments. Thus, due to the increased requirement of substantial activity, in the long run not only IP assets but genuine research activity may be shifted.   In this project, we relate the main features of the current (European) patent box regime and the modified nexus approach to forward-looking measures of the cost of capital and the effective average tax rate. We build on the established methodology of Devereux and Griffith and extend existing work covering the period before the introduction of the Modified Nexus Approach. Based on the measures of the effective tax burden, we draw conclusions on the attractiveness of the location for research activity, policy effectiveness and residual tax planning strategies of multinationals.