In a general equilibrium framework, this paper studies the properties, in terms of labour market distortions and capital accumulation, of three social security systems: a pay-as-you-go notional defined contribution (PAYG NDC), a fully funded (FF), and a novel modified FF (MFF) system, which includes an intragenerational redistributive component to guarantee minimum living standards to future low-income retirees. We show that while PAYG NDC depresses labour supply and physical capital accumulation, FF is neutral on both dimensions. Conversely, MFF slightly increases physical capital accumulation, without significantly reducing labour supply incentives. Moreover, it reduces the burden of future intergenerational redistribution, and increases social welfare.