For such reasons, policy problems are often divided into "messy" (complex) and "not messy" (simple) categories. The issue is how one should define and distinguish problems for decision making in order to resolve present problems and prevent future policy crises. Coherent, unmessy problems are rare in public-sector work and usually involve routine support matters such as personnel and internal management. Note, however, that routine matters can get out of hand and tum into messy, "high"-policy problems. For example, pine beetle infestations have been occurring for thousands of years and are thought to be cyclical. Foresters have traditionally targeted forests with a range of tools that have been more or less effective at preserving the economic and ecological value of pine forests. When these tools failed, all that was lost were a few forests. Now pine beetles have infested millions of acres of trees in the American West. The once-simple problem has now become complex: Global warming has:prevented normal destruction of larvae under the bark, leading to more rotting forests and increased carbon emissions, and jeopardizing policy goals to reduce carbon emissions to 17% of 2005 levels by 2030 (New York Times 2009). What had been a simple and local operational problem now affects policies that target messy and complex international problems of how to regulate greenhouse gases and best stimulate alternative sources of energy supplies.
Third, and finally, precise definition of a problem is confounded by the face that
there can be many interpretations of the same information. Different problem definitions derive from the fact that different constituencies or