The "activity" RSA component of the active solidarity income, providing financial support in a sustainable manner for households with low incomes, is a means of combatting the phenomenon of in-work poverty. But this component, which is the main innovation of the RSA, has not made an impact: nearly seven out of ten households who were eligible for the "activity" RSA in December 2010 have not used it. While the main studies on the non-use of the RSA have focused on its root causes, this article looks at the impact of non-use on inequality and poverty. Drawing on a survey of RSA beneficiaries by the DARES, the aim of the first part of the article is to describe households which have not used the "activity" RSA and to estimate the probabilities of non-use associated with the socio-demographic characteristics of eligible households. The risk of non-use is greater for households without children, those eligible for small RSA sums and those where members have a stable job. Using these probabilities of non-use in a microsimulation model of social and fiscal transfers (Myriad), the second part of the article highlights the financial impact of non-use of the "activity" RSA. At macroeconomic level, the inefficiency which this generates in the fight against poverty is low in scale. However, at individual level, financial losses for non-user households are not negligible, in the order of 100 euros per month for households in the first standard of living decile.