Ruch Prawniczy, Ekonomiczny i Socjologiczny, 1981, nr 4
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Browsing Ruch Prawniczy, Ekonomiczny i Socjologiczny, 1981, nr 4 by Author "Janc, Alfred"
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Item Model demograficzny w zastosowaniu eksperymentalnym(Wydział Prawa i Administracji UAM, 1981) Mazur, Denis Peter; Janc, AlfredA demographic model of fertility age curve is simulated to determine the effect of successive shitfs in women's aggregate age at birth. The age limits of women's reproductive span their age structure, and the annual number of livebirths are held constant in the first experiment" The second experiment involves an assessment of variation in women's reproductive-age span, Two experimental populations are distinguished: (1) the actual population by age, and (2) the life table type. The shape of age curve of fertility has a minimal affect on the cumulative rate for the life table age structure. When based on the actual population by single years of age, the cumulative rate of total fertility tends to fluctuate with changes in the peak age of women at childbearing. An increase in the average age of women at birth under the absolute constancy of parameter values usually augments the rate of total fertility. A slight decrease in completed fertility is observed for the life table type of age structure when the upper limit of women's reproductive span is advanced early. In the final simulation, when requirement of the constancy of parameter values is much relaxed the test corresponding to an intermediate value of the average age at childbearing generates the highest level of completed fertility. The author suggests that the most desirable approach seems to be a combination of analytic properties of the model with simulation.Item O potrzebie opracowania koncepcji i metody szacowania struktury ludności bez zniekształceń i zakłóceń(Wydział Prawa i Administracji UAM, 1981) Valkovics, Emil; Janc, AlfredThe interpretation of age-pyramids representing population structures qualified as distorted may be found mostly in the form of specifying the causes of „cuts" and „protrusions" seen on them, without taking their multiplying effects exerted mostly on the number of birth into consideration. The calculation of age-pyramids or population structures referring to identical dates of observation necessitates to eliminate the effects deemed as causing distortions, occured extraordinarily during the century preceding the observation of the population on the life history of each of the birth cohorts (generations) constituting the population. After calculating (estimating) the population sùrplusses or losses regarded as extraordinary, as well as their structures, we have to elaborate the hypotheses on mortality, nuptiality, fertility and external migration of their — and of their descendants — further lives. Afterwards, on the basis of fictive numbers of the populations of the related birth cohorts for the termination of the effects causing distortions up to the date of the observation „population projections" are to be realized. The age-pyramid and population structure without distortion may be compared with the real (distorted) age-pyramid and population structure in several ways. The calculation of the structure of subpopulations without any perturbation — constituting the population — necessitates also the elimination of the effects of differences in the mortality and external migration of the subpopulations, beyond the so-called rectangular standardization of the age-specific rates of the subpopulation observed transversally. If it is not possible, we have to apply the hypotheses of independency and continuity. However, neither the elimination of the effects of differences observable in the calendar within the individual cohorts concerning the longitudinal sums of the age specific rates of subpopulations can be neglected. Beyond the transversal population structures without any distortion and perturbation, also their longitudinal versions referring to individual birth cohorts (generations) can be calculated, as they are in interrelation with the transversal versions of the former one, that may be described also in mathematical way.