ABSTRACT Most efforts to analyze and forecast interregional population growth and distribution are hampered by the general paucity of reliable data on interregional migration. This has led demographers to rely on crudely constructed measures of net migration. Recent efforts to express the population growth process in matrix form, however, suggest a means whereby the schedule of growth that operates in an interregional system may be estimated solely on the basis of historical data on interregional population distributions. Such a method ist described and illustrated in this paper. The method estimates a growth regime which, when applied to the initial interregional population distribution in the time series, most closely reproduces the remaining population distributions in the historical sequence.