This book describes the development of a vacancy chain-based tool to simulate labour market ?ows. Drawing on a work-history dataset covering the whole of the Austrian population, ''in?ow-out?ow tables'' were established at both the national and the regional level in a breakdown of 28 sectors over the period 2003-2007. These tables summarise observed worker flows within and between industries, as well as flows between different labour market states. Assessments of the inflow of workers to different sectors and simulations of workforce absorption were performed based on the tables. Further, it could be shown how regional specialisation results in different patterns of sectoral job mobility when subjected to similar external shocks. The simulations were carried out on the assumption that jobs as a resource can be handed over interpersonally and so result in vacancy chains of opportunity. This approach explicitly accounts for sectoral interlinkages at the labour market in contrast to the aggregate-matching function which leaves inter-sectoral mobility in a black box.