What social security: Beveridgean or Bismarckian?

Why are Bismarckian social security systems associated with largerpublic pension expenditures, a smaller fraction of private pension andlower income in-equality than Beveridgean systems? These facts arepuzzling for political economy theories of social security whichpredict that Beveridgean systems, involving intra-generationalredistribution, should enjoy larger support among low-income people andthus be larger. This paper explains these features in a bidimensionalpolitical economy model. In an economy with three income groups,low-income support a large, redistributive system; middle-income favoran earning-related system, while high-income oppose any public system,since they have access to a superior saving technology, a privatesystem. We show that, if income inequality is large, the voting majorityof high-income and low-income supports a (small) Beveridgean system,and a large private pillar arises; the opposite occurs with lowinequality. Additionally, when the capital market provides higherreturns, a Beveridgean system is more likely to emerge.