What are the potential advantages and drawbacks of proposals to create a Capital Market Union in the EU? This Policy Brief discusses the long-term implications of perfectly integrated capital markets, ignoring crises but taking population aging into account. Recent research shows that redistribution would take place, from fast aging to slow aging countries, because investors seek access to the largest labour markets that deliver the highest returns on their investments. In some countries like Austria social security reforms like raising the retirement age would play a crucial role in maximizing the benefits of CMU, or minimizing related losses.