In many cases, floodplains do not just affect flood risk, but have additional outcomes in terms of biodiversity and landscape. Not only would these elements be usefully included in cost-benefit analysis, but also in the design of agri-environmental policy tools targeting a bundle of environmental goods. This raises the issue of additionality of ecosystem services and potential stacking of ecosystem services payments, on which the OECD has recently devoted work (Lankoski et al.,