Simultaneous equation models, increasingly used in many detailed analyses, tend to get larger and more sophisticated to describe the structure of the study area to be close to the actual situations. In setting up such a system of equations, statistical results and simulation performance of the model as a whole may be meaningless and unrepresentative of the real world due to a structural instability that is built into the model when the equations are combined and solved simultaneously. Even though the use and subsequent analysis of an unstable system are likely to mislead us, most of the studies that take the simultaneous equation approaches neglect such a serious problem. Thus it is necessary to illustrate how to check the stability problem and apply to the actual model, then investigate how such as analysis is able to provide useful information about the structural characteristics of the model from the dynamic viewpoint.