The paper discusses a notion that figures in Karl Marx’s Capital and is often employed with respect to migration. What I have in mind is the notion of industrial reserve army. I start by discussing the critique of this notion developed by Yann Moulier Boutang in his book De l’Esclavage au salariat. I then emphasize the background of that critique, focusing on the fact that the concept of industrial reserve army is often employed to stig- matize migration. Nonetheless I ask whether other uses of the notion are possible. To this aim I turn to Marx’s Capital in order to demonstrate that his understanding of the industrial reserve army is flexible and nuanced. I focus in particular on his analysis of mobile and “nomadic” populations and I end by reflecting on the multiple shapes that the Marxian problematic takes in the present. The concept of “potential labor,” often employed in research reports of ILO in recent years, provides an important entry point in this respect
