This paper studies the ability of the political process to design public policies implying an effective and efficient provision of global and local environmental public goods. While it is commonly accepted that the market is unable to guarantee an efficient provision of public goods, such as environmental protection or food security, the question is if or under which condition political processes are efficient mechanisms of public good provision. Beyond policy failure due special interest politics policy failure also results from the fact that economic processes are often rather complex and hence laymen use simple mental models (political beliefs) to understand policy impacts. If political beliefs are biased political decision making based on public opinion leads to rather inefficient policies establishing the paradox of populist democracy policy failure. We use own choice experiment data on sustainable land use policy in Germany to estimate econometrically the WTP for relevant global and local environmental public goods as well as voters' political willingness-to-vote for specific land use policies. Based on these estimations we derive underlying political belief. Further, we assess to what extend a populist democracy policy failure results, i.e. to what extend policy choices driven by political beliefs imply inefficient land use policies when compared to the counterfactual evidence-based policy choices driven by model-based technological relations.