Young women disproportionately migrate from eastern to western Germany, leaving behind a historically unique imbalance in the gender ratio in many East German regions. In some East German counties, 100 men between 20 and 30 years of age are faced with less than 80 women of the same age. An improved understanding of the causes and consequences of this recent development is of high policy relevance. The project seeks to empirically examine the relationship between gender ratios, labour market outcomes and social stability based on a regional analysis. As a starting point, both the temporal and spatial pattern of the gender ratio at the level of the German counties are to be described. Based on econometric techniques, a second part of the project aims at identifiying the impact of the labour market and the marriage market on regional gender ratios. However, the main focus of the project will be to identify the causal impact of the gender ratio on labour market outcomes and social stability.