The drivers of cross-country differences in SA benefit dynamics are difficult to determine based alone on the administrative data used in this subsection. Some of the observed patterns are likely due to institutional features of the benefit systems, for instance the strictness of eligibility criteria or the availability of active labour-market programmes. Unfortunately, recent cross-country evidence on the design of social assistance policies is relatively rare (for an exception, see Immervoll (2012a)). Where SA is administered at the local level - as for instance in the Netherlands, Norway and Sweden - within-country policy variation can moreover be large.