This assumption is relatively innocuous for factors such as measures of labour market tightness such as local unemployment rates or measures of benefit generosity. More debatable is the supposition that the impacts of shocks in individuals’ SA receipt on where they live, the type of housing, or their household composition, are sufficiently small that they may be ignored. This is a model specification issue because endogeneity issues can be addressed in principle by extending the basic DREP specification to also model the determinants of endogenous factors jointly along with the model of SA receipt.