Suchergebnisse

AbstractSystem dynamics models are often constructed to improve system performance by identifying and modifying feedback mechanisms that drive system behavior. Once identified, these feedback mechanisms can be used to design and test policies for system performance improvement. A preliminary step in developing policies is the identification of high‐leverage parameters and structures, the influential model sections that drive system behavior. The current work clarifies and extends the use of statistical screening as a tool to improve model understanding, explanation, and development with a six‐step process. Statistical screening adds rigor to model analysis by objectively identifying high‐leverage model parameters and structures for further analysis. Statistical screening offers system dynamicists a user‐friendly tool that can be used to help explain how model structure drives behavior. Copyright © 2009 John Wiley & Sons, Ltd.

AbstractIncreased societal risks due to the anthropogenic degradation of natural systems often require public policy action to mitigate. For example, increased skin cancer risks associated with anthropogenic stratospheric ozone depletion led to public policies limiting the emission of many ozone‐depleting substances. Natural–societal system interaction is complex and often requires expert knowledge and technology to develop effective and sustainable societal risk mitigation policies. However, available knowledge and technology are not always successful in increasing policy makers' attention to or understanding of these risks. The current work uses a system dynamics model of a feedback system that describes the stratospheric ozone depletion case to identify high leverage points for domain experts to influence policy makers in addressing risks posed by changes in a natural system. Model analysis suggests that the rate at which policy makers' attention to natural system risk is increased has a significant influence on the development of knowledge and technology and the ability of policy makers to mitigate societal risks. Copyright © 2011 System Dynamics Society.