Różnice w pomiarze płodności kobiet zależnie od szacunku liczby ludności

Abstract

The primary objective of the article was to present the differences in women’s fertility measurements in Poland depending on the method of estimating the population number. An additional aim was to determine the variability of fertility rates by age and geographical region as a consequence of the adopted definitions of population. The study used data from Statistics Poland, Eurostat and the Human Fertility Database for 2021, taking into account changes in women’s fertility starting from the 1945 generation. Demographic, period and cohort analysis methods were employed in the study. The longitudinal approach was used to additionally identify changes in fertility patterns across generations of women. In accordance with the principle of constructing demographic coefficients, the number of events was related to the population that could actually experience them, i.e. the resident population. All partial fertility rates were recalculated based on the estimated resident population according to the Population and Housing Census 2021. The results of the analysis indicate that total fertility rate (TFR) of women in Poland in 2021 calculated for the population according to the national definition was lower by 4.3% than the rate calculated for the resident population. The most significant underestimation was observed for the 35–39 age group (by 6.3%), and in terms of geographical regions, for Podkarpacie (by 11.0%). The discrepancies are larger for age groups and regions with greater mobility, showing the need to take into account the resident population when measuring the intensity of demographic processes.