In this article, we stress the effect of a Negative Income Tax (NIT) scheme on the firms' behaviour as regards their technological choices. Within the framework of a matching model with differentiation of the agents, we show that a NIT reduces inequalities and rises employment making agents less selective. Moreover, the repercussions of such a policy as regards technological choices are generally underestimated. We show that the introduction of a NIT can encourage the firms to invest in skill substitutability. In other words, they can be brought to lead a “despecialisation” of the jobs offered to the workers which is prejudicial to the productivity, in particular in the long run.