evidence: In contrast to imposing an upstream tax on retailers as in the case of Denmark, in March 2002 Ireland introduced a downstream product tax of €0.15 per plastic bag levied on consumers, which led to a 94 per cent reduction in per capita yearly bag use from 328 to 21. However, surveys provided by the Irish Central Statistics Office indicate that plastic bag usage rose to 30 bags per capita in 2006. In July 2007, the Irish government further increased the environmental levy on plastic bags to €0.22 per bag in order to maintain its impact (Irish Department of the Environment, Heritage and Local Government, 2007). The success in terms of substantially reducing the use and the associated gains in the form of reduced litter and a more attractive landscape in Ireland has attracted considerable international interest (Convery et al., Reference Convery, McDonnell and Ferreira2007). However, the seemingly similar legislation of a downstream product charge implemented in South Africa in 2003 witnessed a gradual rebound in plastic bag consumption after showing an initially significant reduction (Hasson et al., Reference Hasson, Leiman and Visser2007; Dikgang et al., Reference Dikgang, Leiman and Visser2012).