Rising levels of urban deprivation and a perception that poverty has become more concentrated in such areas and has taken on a qualitatively different character have provoked a variety of popular and academic responses. The potentially most fruitful set of hypotheses focus on the unintended consequences of social change. A combination of weak labour force attachment and social isolation are perceived to lead to behaviour and orientations that contribute to a vicious circle of deprivation. In examining the value of this conceptual framework in the Irish case we proceed by measuring directly the social psychological factors which are hypothesised to mediate the 'underclass' process. A significantly higher level of poverty is found in urban public sector tenant households. This finding cannot be accounted for entirely by socio-demographic differences. It is the assessment of this net or residual effect that is crucial to an evaluation of vicious circle explanations. Controlling for the critical social-psychological factors we found that net effect was reduced by less than a quarter and concluded that the remaining effect is more plausibly attributed to the role of selection than to underclass processes. Analysis of the changing relationship between urban public sector tenancy and poverty provides support for this interpretation. For the main part the distinctiveness of social housing tenants is a consequence of the disadvantages they suffer in relation to employment opportunities and living standards. Ultimately it is these problems that policy interventions, whatever the level at which they take place, must address.