International tax law allows, under certain circumstances, to considerably reduce the group average tax rate. In some cases, even the tax-free repatriation of yields on intragroup finance is possible, in particular when using hybrid finance. These cases are normally connected to complex questions of foreign, domestic, and bilateral tax law as well as to uncertainty on whether the intended tax consequences will be upheld by the fiscs in future years. We experimentally investigate the two key variables, legal uncertainty and tax complexity while controlling for decision makers' risk attitude. Results show that overall tax complexity has a negative effect on the probability to choose a hybrid finance instrument, while legal uncertainty has not. The impact of the two factors is moderated by decision makers' risk attitudes. (author's abstract) / Series: Discussion Papers SFB International Tax Coordination