Towns (and villages): definitions and implications in a historical setting

The measurement of urbanization rates and other uses of statistical information, for example the use of historical town growth to measure long-term economic growth, are usually based on an ad hoc population threshold to define and practically classify settlements as towns. The method, however, trades off accuracy and precision for convenience and simplicity. This paper proposes a new threshold that uses the town size distribution together with agricultural data to derive an appropriate cutoff value. The relevance of agricultural income is integrated into the classification scheme through the differential effect of local agricultural endowments on settlement size. The threshold is chosen such that the size of towns above the cutoff is statistically not influenced by local agricultural endowments, while the size of villages, which is below the threshold, is indeed shaped by them. This new approach is practically demonstrated with an application to the urban system of the nineteenth century in the German region of Saxony. This setting is used to investigate the relevance of a different classification for the development of urbanization over time and Gibrat’s law. The results demonstrate that the underlying classification scheme matters strongly for the conclusions drawn from historical urban data. They also indicate that the use of a common population threshold for a comparative analysis or temporal comparisons in a historical context increases the misclassifications of settlements.