The link between poverty, and child labor has traditionally been regarded as well established. But recent research has questioned the validity of this link, claiming that poverty is not a main determinant of child labor. Starting from the premise that child labor is not necessarily harmful, the authors analyze the determinants of harmful child labor, viewed as child labor that directly conflicts with children's accumulation of human capital, in an effort to identify the most vulnerable groups. Identifying these groups might enable policymakers to take appropriate action. The authors estimate the positive relationship between poverty, and child labor. Moreover, they find evidence of a gender gap in child labor, linked to poverty. Girls as a group (as well as across urban, rural, and poverty sub-samples) are consistently found to be more likely to engage in harmful child labor, than boys. This gender gap may reflect cultural norms (an issue that calls for further research). The incidence of child labor increases with age, especially for girls. In Ghana, there are structural differences - across gender, between rural and urban locations, and across poverty quintiles of households - in the processes underlying child labor.