»Herrschaft und Staatseinkommen in Ägypten und Rom: Zur Wechselwirkung von Politischer Stabilität und Besteuerung«. This paper investigates what determines fiscal institutions and the burden of taxation using a case study from ancient history. It evaluates Levi's model of taxation in the Roman Republic, according to which rulers' high discount rates in periods of political instability encourage them to adopt a more predatory fiscal regime. The evidence for fiscal reform in the transition from the Republic to the Principate seems to support her hypothesis but remains a matter of debate among historians. Egypt's transition from a Hellenistic kingdom to a Roman province under the Principate provides an analogous case for which there are better data. The Egyptian evidence shows a correlation between rulers' discount rates and fiscal regimes that is consistent with Levi's hypothesis.