Shrinking populations mean less growth and a more fractious world

Sooner or later, therefore, every big economy will collide with a demographic wall. The bill from pensions and hospitals will pile on fiscal pressure. Sapped of workers and ideas, economic growth could collapse while public debt balloons. Just how catastrophic the situation becomes depends on whether policymakers maintain budgetary discipline, withstand pressure from angry older voters and, crucially, are willing to inflict pain on populations now in order to save future generations from more later on.