Short-Cut Methods of Forecasting City Population *

M ARKET analysts often need city population forecasts, but lack the time, money and demographic know-how to make them with the required accuracy and speed.' Available forecasts by chambers of commerce are notoriously overoptimistic, and projections reported by city planning commissions are seldom an improvement. The market analyst is thus forced to rely on his own resources. Unfortunately, he is seldom a specialist in demographic prognostication, and, even if he is, can hardly hope to devote more than a short time to making the necessary projections. Under these circumstances, the analyst wants to know, first, what short-cut methods of forecasting city population are available, and second, how accurate they are. Unfortunately, no complete, up-todate answer to these questions appears in recent literature. The present paper attempts a first approximation of such an answer. At least a dozen distinct methods of forecasting city population have been proposed or used during the past thirty years. Most popular, objective, and readily used of this number are the analogy method, arithmetic and geometric projection, the logistic curve, and both short and long forms of the ratio method. Others are either far more complex, less frequently used, or dependent on subjec-