A new approach to investigating public decision problems is suggested. The use of the approach is illustrated via analysis of long-term development strategies for a national economy. The approach presented is based on the Generalized Reachable Sets (GRS) method developed by one of the authors. The method itself is quite universal and can be used for many purposes. When an economic system's performance indicators (objectives) are given, the GRS method provides a tool for multiobjective evaluation of the system's potential possibilities. In this paper the GRS method is applied to the investigation of a simple model describing transition from an ‘old’ polluting technology to a ‘modern’ clean technology by taking into account levels of consumption, pollution and unemployment.