Reform der Gesetzlichen Rentenversicherung durch die Einführung einer Zusatzrente auf Kapitalbasis: Ergebnisse von Modellrechnungen bis zum Jahr 2045

Es ist mittlerweile weitgehend unbestritten, dass der demographische Wandel eine grundlegende Reform der gesetzlichen Rentenversicherung erforderlich macht. Dies soll im Wesentlichen durch die Einführung einer Zusatzrente auf Kapitalbasis (Teilkapitaldeckungsverfahren) erfolgen. Der Beitrag präsentiert einen Vorschlag für eine derartige Reform, im Besonderen zeigt er aber, welche Konsequenzen sich darauf für die Ausgaben und den Beitragssatz der Rentenversicherung ergeben. Die Ergebnisse der Modellrechnungen legen die Empfehlung nahe, mehrere Maßnahmen miteinander zu kombinieren, den Einstieg in die Zusatzrente in erster Linie mit einer moderaten Absenkung des Rentenniveaus zu verbinden, um den Beitragssatzanstieg zu dämpfen. Sensitivitätsrechnungen zeigen, wie sich eine Änderung wesentlicher Annahmen auf die Ergebnisse auswirkt. Zwar sieht es so aus, als sei die Diskussion um die Ausgestaltung der Reform weitgehend abgeschlossen. Wir sind jedoch der Meinung, dass der Regierungsentwurf zwar die richtige Weichenstellung vornimmt, dass es in den kommenden Jahren jedoch noch umfangreichen Nachbesserungsbedarf geben wird, wozu unser Konzept einen Beitrag leisten könnten --

Psychological profiling : Analysing spatial patterns of convicted serial arsonists

Arson is a major problem nationwide, with local authorities investigating arson cases daily. To help combat this issue, a national study was conducted which focussed on the geographical distribution of arson offences in relation to the offender's home base. The purpose of the current study was to evaluate the utility of Canter and Larkin's (1993) circle theory and home range hypothesis for predicting geographical patterning of serial arson offences in New Zealand. This was achieved by examining offence locations of 45 serial arsonists convicted between 1988 and 2003. Each offender's offence sites and home base were plotted on a scaled street map, replicating Canter and Larkin's (1993) geometric technique for constructing the criminal range circle. An initial test showed that a majority of offenders committed their offences within a distinct offence region. It was also found that the breakdown of commuter- and marauder-type offenders was different from Canter and Larkin's (1993) study of UK serial rapists, suggesting that the marauder model is not universally applicable to account for all types of serial offending. However, the home range hypothesis was supported in this study. Additionally, there was support for the existence of a safety zone around the offender's home base as proposed by Brantingham and Brantingham (1981). Lastly, the current study supports the hypothesis that offenders travel short distances to commit their arsons. Overall, Canter and Larkin's (1993) circle theory and home range hypothesis successfully describe the geographical patterning of offences by serial arsonists in New Zealand. Although the marauder model IS not universally applicable, it still offers potential benefits as part of an investigative tool for local authorities

On the geometric dilation of closed curves, graphs, and point sets

The detour between two points u and v (on edges or vertices) of an embedded planar graph whose edges are curves is the ratio between the shortest path in in the graph between u and v and their Euclidean distance. The maximum detour over all pairs of points is called the geometric dilation. Ebbers-Baumann, Gruene and Klein have shown that every finite point set is contained in a planar graph whose geometric dilation is at most 1.678, and some point sets require graphs with dilation at least pi/2 = 1.57... We prove a stronger lower bound of 1.00000000001*pi/2 by relating graphs with small dilation to a problem of packing and covering the plane by circular disks. The proof relies on halving pairs, pairs of points dividing a given closed curve C in two parts of equal length, and their minimum and maximum distances h and H. Additionally, we analyze curves of constant halving distance (h=H), examine the relation of h to other geometric quantities and prove some new dilation bounds.Comment: 31 pages, 16 figures. The new version is the extended journal submission; it includes additional material from a conference submission (ref. [6] in the paper

Coordination between growth, phenology and carbon storage in three coexisting deciduous tree species in a temperate forest

In deciduous trees growing in temperate forests, bud break and growth in spring must rely on intrinsic carbon (C) reserves. Yet it is unclear whether growth and C storage occur simultaneously, and whether starch C in branches is sufficient for refoliation. To test in situ the relationships between growth, phenology and C utilization, we monitored stem growth, leaf phenology and stem and branch nonstructural carbohydrate (NSC) dynamics in three deciduous species: Carpinus betulus L., Fagus sylvatica L. and Quercus petraea (Matt.) Liebl. To quantify the role of NSC in C investment into growth, a C balance approach was applied. Across the three species, >95% of branchlet starch was consumed during bud break, confirming the importance of C reserves for refoliation in spring. The C balance calculation showed that 90% of the C investment in foliage (7.0–10.5 kg tree −1 and 5–17 times the C needed for annual stem growth) was explained by simultaneous branchlet starch degradation. Carbon reserves were recovered sooner than expected, after leaf expansion, in parallel with stem growth. Carpinus had earlier leaf phenology (by ∼25 days) but delayed cambial growth (by ∼15 days) than Fagus and Quercus , the result of a competitive strategy to flush early, while having lower NSC levels