However, recent contributions to this debate have attempted to exclude Marxism from the discussion. These contributions maintain that, because Marxist theory failed to understand the centrality of unfreedom to modern capitalism, a new explanation of this link is needed. This claim has been questioned by Tom Brass (2014), ‘Debating Capitalist Dynamics and Unfree Labour: A Missing Link?’, The Journal of Development Studies, 50:4, 570–82. He argues that many of these new characteristics are in fact no different from those identified earlier by Marxist theory and that the exclusion of the latter approach from the debate is thus unwarranted.