ABSTRACT This article explores the effects of scientific governance on personal liberty in interwar Britain through the work and life of German-Jewish demographer Robert René Kuczynski. Kuczynski arrived in Britain as a refugee in 1933 and, within the span of a few years, moved from being a researcher and reader at the London School of Economics to becoming demographic adviser to the Colonial Office. In the service of the British government, Kuczynski realized the first complete demographic survey of the British (...) Empire. Based on extensive primary research at the London School of Economics Archives and the Zentral- und Landesbibliothek Berlin, this article analyses the complex ways in which Kuczynski’s experience as a forced intellectual migrant interacted with – and often contradicted – his scientific work on population and the national and imperial policies that were enabled by it. Doing so, this article points to the inadequacy of merely evaluating personal freedom by means of law and power politics and asks about the hidden constraints in technocratic governance based on scientific knowledge. (shrink)