A Method of Graphical Analysis

I N connection with many telephone problems of an economic character, it is necessary to develop methods for making estimates and forecasts of the effects of changes in conditions. When the changes in conditions are such that direct experimentation is impracticable the development of logical methods and bases for estimates involves analyses of past experience in specific situations and, in so far as is feasible, the generalization of such experience. It is the purpose of this paper to describe briefly a graphical method by which complex economic data may be generalized for use in forecasting probable future conditions. In some problems, it is necessary to determine the effects of changes in a specific situation, the results being applicable particularly to the given situation, and only very generally to other situations. The effect of a change in population upon station growth in a given exchange is an example of such a problem. In other problems, it is practicable to generalize experience so that the results of analyses may be applied, under proper conditions and limitations, to various specific situations. Moreover, it is often necessary to apply a general conclusion to a specific situation because no specific experience is available. An example of this type of analysis is the generalization of results of various rate treatments in different exchanges. In meeting this type of problem graphical methods are utilized to compare experience of a similar nature in various situations.