In Responding to Global Poverty: Harm, Responsibility, and Agency, Christian Barry and Gerhard Øverland address the two types of argument that have dominated discussion of the responsibilities of the affluent to respond to global poverty. The second type of argument appeals to ‘contribution-based responsibilities’: the affluent have a duty to do something about the plight of the global poor because they have contributed to that plight. Barry and Øverland rightly recognize that to assess contribution-based responsibility for global poverty, we need to understand what it is for an agent to contribute to harm rather than merely failing to prevent it. Barry and Øverland argue that we should replace the traditional bipartite distinction doing and allowing with a bipartite distinction between doing, allowing and enabling. I argue that their discussion represents a significant contribution to this debate. However, more detail on their key ideas of ‘relevant action’ and ‘complete causal process’ is needed. Moreover, in cases involving the removal of barriers, the non-need based claims of those involved matter.