Social policies are designed to tackle vulnerability processes, providing additional resources to vulnerable target groups and helping them overcome stressing situations. However, empirical observations have shown that social policies may also reinforce vulnerability in certain cases. This can be better explained if one considers vulnerability as a multi-level process. Vulnerability is experienced by individuals at micro-level: it is then characterised by multidimensionality where diverse spheres of life can be affected; vulnerability is then framed as a social issue at macro level, requiring the setting up of adequate policy; this macro notion of vulnerability is then implemented at meso-level by agents that are called to translate the macro level notion of vulnerability into actual public action. There may be a gap or a discrepancy between the different notions of vulnerability as experienced at micro level, framed as social problem at macro level and implemented as public action at meso level. This gap may result in paradoxical situations where social policies do not provide adequate resources or submit their access to stringent conditions acting as stressors, thus reinforcing cumulative disadvantage rather than counteracting it. Examples from studies conducted within the NCCR-LIVES illustrate some of these paradoxical situations.