Age waves of baby boom and baby bust generations through arithmetic and geometric coefficients of population ageing in Serbia

Abstract

Age waves is theoretical concept that take into account the importance of disordered cohort flows, mainly as by-product of demographic transition (fluctuating fertility and improved survival), but also external factors (especially wars). The primary age wave as a consequence of high births after the Second World War in Serbia did not remain an isolated phenomenon, but created a secondary cohort wave although the fertility indicators were declining, which is visible as the thickening of the pyramid base in 1981 due to the absolute increase in births. Cohort "tide" has influenced the shape of the pyramid to longer retain the properties of the stationary type because the baby boom generation reproduced the "echo" generation, which is a counterbalance to extreme demographic aging as the baby boom generation entered the contingent of the old population. A cohort analysis of the elderly population shows that the declining share of the elderly in a certain age group is typical for cohorts born during turbulent times, most often wars, while cohorts born afterwards form more numerous generations. A half-century characteristic of the Serbian population is an absolute increase of people older than 65, but it does not automatically mean an adequate increase in the relative share of the elderly because it depends on the number of other age groups and their cohort trajectories. The methodological tool that can valorize heterogeneity of the old population is important for societies with past oscillations in fertility and migratory movements. In this study, the usefulness of the arithmetic and geometric coefficients of aging was tested on the example of baby boom and baby bust generations and their position in the old population, revealing periods when rejuvenation or aging of the old has dominated.

Kohortno talasanje je teorijski koncept koji uvažava značaj neregularnih kohortnih tokova kao nusprodukta demografske tranzicije (fluktuirajući fertilitet i produženo očekivano trajanje života), ali i eksternih faktora (posebno ratovi). Primarni "starosni talas" kao posledica visokog rađanja nakon Drugog svetskog rata nije ostao izolovan fenomen, već je generisao sekundarno kohortno talasanje što potvrđuje i zadebljanje baze piramide 1981. godine nastalo zbog apsolutnog povećanja rođenih. Kohortno talasanje je uticalo da oblik piramide duže zadrži svojstva stacionarnog tipa jer je bebi bum generacija reprodukovala "eho" generaciju, koja je predstavlja protivtežu ekstremnom demografskom starenju pošto je bebi bum generacija ušla u kontingnet starijih od 65 godina. Analiza starog stanovništva pokazuje da opadanje udela starih u određenoj starosnoj grupi po pravilu znači da je TA kohorta rođena tokom vremene turbulentnih vremena, najčešće ratova, dok oni rođeni posle ratova formiraju brojnije generacije. Ali treba naglasiti da apsolutni porast starijih od 65 godina, što je poluvekovna karakteristika stanovništva Srbije, ne znači i automatski adekvatan porast relativnog udela starijih jer on zavisi od broja ostalih starosnih grupa, ali i od kohortnih trajektorija. Novo metodološko rešenje dopušta da se valorizuje heterogenost starog stanovništva i čini se vrlo praktičnim u društvima u kojima je dolazilo do velikih oscilacija fertiliteta i izrazitih migratornih kretanja. U ovom istraživaju je testirana korisnost koeficijenta oštrine i dubine starenja na primeru krnjih i kompenzacionih generacija i njihovoj poziciji u starom stanovništvu, otkrivajući periode kada je dominiralo podmlađivanje starog stanovništva, odnosno kada je nastupalo izraženije starenje starih.