Age- and Duration-Specific Dynamic Models
Altersspezifische, dynamische Arbeitsnachfrage
Gustav Feichtinger, Alexia Fürnkranz-Prskawetz
Gegenstand dieses Projekts ist die Erweiterung dynamischer Arbeitsnachfragemodelle durch Einführung einer altersstrukturierten Kostenfunktion der Anpassungskosten sowie einer zweiten Zustandsvariablen, welche das Humankapital der Arbeitskräfte über die Zeit beschreibt. Neben dem Zu- und Abstrom der Arbeitskräfte wird somit eine zweite Kontrollgröße betrachtet, welche die optimale Investition in Humankapital beschreibt. Ziel ist eine Charakterisierung der optimalen Arbeitsnachfrage und Humankapitalinvestition in Abhängigkeit von altersspezifischen Anpassungskosten.
Vorbeugung und medizinische Behandlung von HIV/AIDS in Afrika
Gustav Feichtinger
Es wurde ein eingeschlechtliches altersstrukturiertes Compartment-Modell mit demographischen und epidemiologischen Daten modelliert und für die HIV/AIDS-Epidemie in Botswana teilweise validiert. Während für die Dynamik interessante Einsichten erzielt werden konnten, ist der Optimierungsteil nach wie vor offen. Über den deskriptiven Modellteil wurde auf Konferenzen in Ouagadougou, Dar Es Salaam und Nairobi berichtet. Am Kosten-Effizienz-Teil, in welchem der optimale Mix von Prävention und medizinischer Behandlung ('vaccinations') ermittelt werden soll, wird weiter gearbeitet.
Demography of a Learned Society
Gustav Feichtinger, Maria Winkler-Dworak, Inga Freund, Alexia Fürnkranz-Prskawetz, Fernando Riosmena (University of Colorado at Boulder)
For some time now, a key issue of scientific research, politics and the media has been the ever-increasing age of the population. This increase is due both to declining birth rates and the rising life expectancy, i.e., to diminishing mortality—specifically in the older age groups. To counteract this trend in the general ageing of the population, policy makers have the possibility to intervene by introducing measures to encourage childbearing or migration. In cases where a population is closed to migration and where early death can be ruled out in the usual course of events, the logic of population dynamics implies that the only alternatives are growing and/or ageing. Hence, we have to live in an ageing population, and the subpopulations of learned societies are no exception to this rule. With regard to the Austrian Academy of Sciences (Österreichische Akademie der Wissenschaften/ÖAW), we have to take into account the restrictive particularity that here the maximum number of members below a certain age threshold is limited. This automatically restricts the influence of the younger cohorts’ age. What options does an Academy have to respond to the increased ageing of its member structure? Should it perhaps not respond at all to this development, as it is a mere reflection of the progressive ageing of our society? The investigations of this project have been aimed to provide answers to the above questions. After a reconstruction of the data we studied the historical developments of the numbers and age structure of the members of the Austrian Academy of Sciences. In particular, we also conducted an in-depth study of the mortality differences of academicians and the Austrian male (alternatively the Austrian highly educated) population. Under the premise that the Academy is interested in keeping a young age structure of its members and, on the other hand, in electing as many new members as possible per year, the statutory maximum number of 45 full members per section implies a conflict between these two objectives. Applying demographic projection methods we showed the effect of the age distribution of new entrants on the number of vacancies each year and the age structure of the members thereby illustrating the above mentioned trade off. A bimodal age distribution of new entrants turned out to be optimal with respect to the above mentioned objective. By applying optimal control theory we sketched that such a policy is indeed an optimal solution under the above objectives. Our study is not only relevant for learned societies but also for other subpopulations, whose dynamics (i.e., temporal development and structuring) can be studied with demographic methods illustrated in this paper. These examples include universities, armies and companies. Formally related are migration dynamics where in- and out-migration can occur at any age.
Publications:
Winkler-Dworak, Maria. 2006. The Low Mortality of a Learned Society. VID Working Paper 05/2006; Vienna Institute for Demography.
Feichtinger, Gustav, Winkler-Dworak, Maria, Freund, Inga and Prskawetz, Alexia. 2007. On the Age Dynamics of Learned Societies: Taking the Example of the Austrian Academy of Sciences. VID Working Paper 02/2007; Vienna Institute for Demography.