This book addresses the universal and topical question of solidarity across generations from a comparative perspective, with a particular focus on the legal issues concerning retirement pensions, the poverty in the elderly, long-term care, as well as state interventions and family support for those at risk. Drawing on insights from the interface between family law, administrative law and social law, it examines 13 countries on different continents, and also briefly covers a number of additional countries in the introduction. This book is a based on the discussions and exchanges at the 20th General Congress of the International Academy of Comparative Law, in Fukuoka, Japan.