Public policies often fail to properly address the problems they are supposed to solve and may lead to unintended consequences as a result of the complexity of the environment they operate in and the flaws of the policy-making process. Ghaffarzadegan et al. (2011, p.3-6) list five factors that generally have a large impact on public policy implementation. The following paragraphs outline these factors, and apply them in details to the case of the German PO. These factors are:”policy resistance from the environment””need to persuade different stakeholders””overconfident policy makers””need to experiment and the cost of experimenting””need for an endogenous perspective”One of the key issues in developing a functioning sociotechnical system is policy resistance. Policy resistance occurs as a result to a policy action taken by a government as a feedback mechanism from the environment that is affected by the policy. Policy resistance is a frequent phenomenon in complex systems with multiple feedback loops. There are several reasons for resistance to policies taken by a governing body in a complex system. One problem is the long time period between feedbacks that can lead to delays between the policy action taken and the outcomes desired. (Ghaffarzadegan et al., p. 3) Secondly, the complexity of the system is sometimes overlooked or not recognized by the actors that are trying to influence the system. While intuitive policies, that appear right at the first sight, seem an ideal choice for policy makers, they might be faced with strong resistance from multiple players involved in the system that do not see the benefits of the policy. In order for policies to be successful all actors involved need to be aware of the implications of decision for the entire system and its actors. This requires learning. However, learning processes are difficult to achieve due to the complex structure of the system (Forrester 1971, Repenning and Sterman 2002).When it comes to the “need to persuade different stakeholders” it can be noticed that policy-making is more than one decision-maker deciding on a course of action that all the affected parties immediately implement. Rather, several groups of stakeholders inside and outside the government should participate in developing policies in order to maximize their effectiveness and ensure the success of a policy measure taken. “Overconfident policy makers” can be another factor that limits the success of policy options. Decision makers’ overconfidence has been studied before by psychologists and decision theory scholars (Lichtenstein and Fischhoff, 1977; Lichtenstein et al., 1982). It affects both novice and expert decision makers. Hood and Peters (2004) point out that government administrators tend to ignore some of the limitations of their knowledge. These limitations can be especially difficult to see when complex systems are involved with time delays and a significant level of uncertainty. Overall, research suggests that overconfidence hinders the policy makers’ ability “to question their assumptions, models of thinking, and strategies” (Ghaffarzadegan et al., 2011, p.3). This makes it difficult to effectively involve a diverse set of stakeholders in the decision making process, and is something that to some extent can be seen in the case of the development of the DPG.To create and implement successful policies the “need to experiment and the costs of experimenting” need to be recognized. As alluded to earlier, the behavior of complex systems is difficult to predict, and it cannot be expected that policies in these environments will immediately lead to the desired effects. Experimentation is thus needed to evaluate the effectiveness of actions, learn from the results and change course if necessary. The fifth factor refers to the “need for an endogenous perspective”. It points to the tendency of decision makers to see unintended or undesirable developments as a result of exogenous elements, i.e. external factors. Individuals with this tendency struggle to learn from mistakes and use experience to change their behavior in a way that leads to better results (Senge, 1990). This phenomenon is described by Sterman as a misperception of feedback (1989). Sterman simulated a supply chain of beer in a game with subjects acting as decision makers. He concluded that over- or under-ordering by the players and the resulting instability of the system were generally attributed to customer behavior, instead of the players’ own decisions, even though customer demand stayed the same after an initial incremental change. Only by taking all five factors into account can successful policies be created and the resistance to a new policy avoided. The factors and how they can be applied to the case of the DPG are expanded on in the results section.