Demográfiai hatások és implicit hozamok kapcsolata a nyugdíjrendszerekben = The relationship of demographic effects and implicit returns in pension systems

E tanulmány központi témája a nyugdíjrendszerek implicit hozama. Az együtt élő nemzedékek figyelembevételével felépülő nyugdíjmodellekben kétféle implicit hozamot különböztetünk meg. A hosszmetszeti implicit hozamot valamely adott nemzedékhez tartozó, különböző években esedékes pénzáramlások alapján, a keresztmetszeti implicit hozamot pedig több, különböző nemzedék adott évben jellemző pénzáramlásai alapján számíthatjuk ki. A hosszmetszeti és keresztmetszeti implicit hozamok értékeit és a közük lévő összefüggéseket a tőkefedezeti, a névleges egyéni számlás és a hagyományos felosztó-kirovó nyugdíjrendszerek egyszerű elméleti modelljeiben hasonlítjuk össze. A számításokhoz használt modellkeret fontos eleme a várható élettartam figyelembevétele. Az eredmények azt mutatják, hogy a maximális és a várható élettartam eltérésekor a hosszmetszeti és a keresztmetszeti implicit hozamok közötti összefüggések még egyszerű elméleti modellben is meglehetősen összetettek lehetnek. ____ The focus of this study is on the implicit returns of pension systems. Two types are analysed using an overlapping generations model: the calculation of longitudinal\" return is based on cash flows in different years belonging to a given generation, while cross-section\" implicit return is calculated in a given year with cash flows of multiple generations. Values and relationships of longitudinal and cross-section implicit returns are compared in simple theoretical models of fully funded\", notional defined-contribution\" and traditional pay-as-you-go\" pension systems. An important element of the theoretical model is the inclusion of an assumption about life expectancy. Model results point to the complexity of the relation between longitudinal and cross-section implicit returns, if expected and maximum life expectancy differ. The study maps and introduces these complex relationships.

The long term preservation of an 18th century gene bank heritage

The allée is one of the oldest instruments and forms of landscape architecture, which has often been used from the Antiquity for the expression of visual and functional relationships, for the delimitation of space, or for the pictorial creation of movement. The several hundred years old allées of the late baroque age, which still live among us as the witnesses of bygone times, represent a special value throughout Europe. The longevity and the respectable size as such bestow a certain value upon the trees. However, the allées also stand for a garden art, landscape, culture historical and natural value, which in a summarized way are called cultural heritage. Furthermore, the gene pool of the proven longevous, high tolerance tree specimens is a natural and genetic heritage of scientific signification. The age of the trees and allées is finite. Even with a careful and professional care, the renewal is inevitable, which, beyond technical problems of landscape architecture might raise many scientific, nature conservation, yes, esthetical and ethical questions. This is why there is no universal methodology, but there are aspects and examination procedures of general validity with the help of which a renewal can be prepared. The renewal concept of the lime tree allée in Nagycenk aims at the protection and the transmission of the value-ensemble embodied in the allée. One part of the value-ensemble is the spiritual, cultural heritage, the extraordinary value of the landscape-scaled, landscape architectural creation planted and taken care of by the Széchenyis. On the other hand the two and a half centuries old trees represent an inestimable botanical and genetic wealth. Its transmission and preservation is a scientifically important program coming up to the Széchenyi heritage. After the registration of the originally planted old trees, the complete nursery material of the “Széchenyi limes” necessary for the replanting can be produced by vegetative propagation. The gradual replacement of the stand with its own propagation material, by the carefully raised nursery trees of the same age can be a model for the gene-authentic renewal method – a novelty even at an international level.