This book advances a reconceptualization of welfare state crises in aging societies. Against the dominant fiscal framing, which reduces demographic pressure to pension arithmetic and healthcare expenditure, it argues that the crisis is structural and temporal. It introduces demographic debt as its defining analytical category: the asymmetry between institutional promises that require future human time and the capacity of shrinking populations to provide it. Unlike fiscal debt, this obligation has no creditor and no procedure of settlement.

The first half establishes how demographic debt emerged from the silent assumption that each generation would be more numerous than the last, and how welfare institutions malfunction once that assumption collapses, producing a deficit of time rather than money. The second half replaces progressive solidarity, which presumes each generation inherits more than the one before, with contractive solidarity, a proportional conception of justice that begins from limitation. It proposes measures of temporal balance across generations, engages the social investment paradigm, and specifies the institutional conditions under which welfare can persist in shrinking societies.

The project challenges an assumption shared by Rawlsian philosophy, mainstream welfare economics and growth-oriented social democracy: that welfare institutions can be evaluated against an expanding baseline. Showing this assumption to be empirically obsolete across the developed world, the book opens a research agenda for temporal welfare studies. It will interest scholars and students of social policy, public policy, economic sociology and population studies.

Stavros Pantazopoulos is Assistant Professor in the Department of Sociology at Panteion University of Social and Political Sciences, Greece. He holds a PhD in social policy and completed postdoctoral research on social transformation. He has authored and co-authored books and articles in international peer-reviewed journals in Greece.

Charalampos Economou is Professor of Sociology and Health Policies in the Department of Sociology at Panteion University of Social and Political Sciences, Greece. He has collaborated with the World Health Organization, the OECD and the European Observatory on Health Systems and Policies, and served as Vice-Rector for Research (2020-2024).