Rodność i umieralność na ziemiach polskich w kontekście teorii przejścia demograficznego

Abstract

An attempt was made, in the article, to explain changes of people's fertility and mortality in ln 1918–1939 in context of the demographic transition as well as to determine transition phase periods. To set the beginning and the end of the "right" demographic transition, the non-linear regression (approximation by anti-logistic function in connection with the simple substitution method) was used in case of rigid fertility and mortality rates. According to the used methodology, it was found the "right" demographic transition (decrease in the mortality outdistanced decrease in the fertility) took place about 1885 on the Polish areas. Important differences in the level and dynamic of the fertility and mortality in different Poland's districts were indicated in the study too. On the basis of estimated models for each district it was stated, i.a. that the earliest (about 1871 and 1875) distinct collapse of the mortality trend took place in the west and south areas. From the time the "right" demographic transition was done on the areas. Moreover, on the basis of mortality tables from the twenty year period between two World Wars, it was recognized the value increase of the average life expectancy as well as a minor increase of the average years number of the reproduction age of the Poland's population (total: men and women).