The demographic situation in Penza region under the reforms of the administrative-territorial division in the 1920–1930s

Background. The obvious unevenness of filling the source base on population movement in the first half of the 20th century forces researchers to develop statistical mod els and use extrapolation or the balance method to obtain the necessary data. But in light of significant administrative and territorial changes in demographic behavior and composition of the population, general models are not always applicable and can give conflicting results. The formation of a transparent systematized cluster of data on the demographic history of the 20th century is one of the most important tasks for historians-demographers, since this issue is exclusively politicized and mythologized. The purpose of the work is to trace the changes in the demographic composition of the Penza region in connection with the change in its borders in the 1920–1930s. Materials and methods. The implementation of the tasks of the study was achieved by processing and systematic analysis of materials from the gen eral censuses of 1897, 1926, and 1939, a collection of legalizations and orders of the RSFSR, comparison of statistical data and cartographic sources. Results. The territorial changes that affected the Penza region in the 1920s and 1930s were systematized. An anal ysis of the size and composition of the population of the former Penza province and the territories of neighboring provinces that later entered the Penza region was carried out. Conclusions. Due to administrative and territorial reforms in the 1920–1930s the borders of the Penza province underwent a radical restructuring, and the composition of the population al so changed significantly. The methods of interpolation and statistical analysis of the demo graphic behavior of the population, used to describe population movement between 1897 and 1928, are not suitable for understanding and describing the demographic picture of the 1930s.