From 2013 the European Union has promoted social investments as a national reform strategy to increase individuals' capacities and national economic growth. However, to take full advantage of social investments, the strategy needs a more coherent framework that takes into account the dynamic and multidimensional nature of social issues and social investments. Theoretically, this article establishes such a framework consisting of generational, life course and gender perspectives on social investments. The generational perspective brings out that social investments involve horizontal redistribution, underpin the productive and reproductive social contract between generations, and the increased diversity within generations. The life course perspective demonstrates how social issues and social investments in one life stage depend on the situation in prior life stages and affect the situation in later life stages and, possibly, in multiple dimensions. The gender perspective shows how social investments can improve economic and social returns when gender and ageing over the life course are taken into consideration. Empirically, cross-national patterns indicate a positive relation between social investment policies and returns.