Mixed policy feedback and evolution of environmental regulation: Analysing instrument recalibration and layering in Danish nitrogen policy

Recent research has demonstrated that positive and negative feedback can occur simultaneously within environmental policy. This tends to occur when policy has multiple purposes. We engage with the concept of mixed feedback to highlight aspects of the phenomenon that have hitherto not been explored in detail and thus add more nuance to the feedback argument to improve our understanding of environmental policy evolution. Our first argument is that single-purpose policies may generate mixed feedback. Each instrument generates distinct feedback. Secondly, we challenge the assumption that negative feedback undermine policy and suggest that negative feedback may indeed contribute to maintaining policy. For policy to endure over longer periods, it needs to respond to feedback. Thirdly, we argue that mixed instrument feedback can result in a substantial reshuffling of an environmental policy mix through the recalibration of instruments. We use the trajectory of Danish regulation aimed at nitrogen run-offs to coastal waters over almost three decades to illustrate the three arguments.