Urban Population Development in Germany (2000-2014): The Contribution of Migration by Age and Citizenship to Reurbanisation

The increase of the population of large German cities between 2000 and 2014 indicates a reurbanisation process in line with the concept of the “growing city”. This exploratory investigation will analyse the influence of internal and external migration on the population development of the German urban system by applying descriptive and statistical methods, going beyond the mere observation of selected cities. This paper shows that reurbanisation in Germany has resulted from various age- and citizenship-dependent combinations of spatial population movements, which in turn express different location advantages and disadvantages. The structural change towards a knowledge economy, the expansion of education, and changing living concepts on the demand versus new urbanistic planning concepts on the supply side strengthen the affinity of different population groups for urban living. This new attractiveness of cities seems to be most distinct among young adults’ motives for living in cities or not. Furthermore, the dynamics of these processes are also dependent upon conditions on the national and international levels. Thus, before the economic and financial crisis 2009 the balances of internal migration of the German as well as foreign population had a decisive influence on the dynamics, in-migration surpluses from abroad rose considerably after 2009. With the rising numbers of asylum seekers, state-controlled residence allocations as well as migrant networks are increasingly important for the population development of cities. At the same time, especially in cities with at least 500,000 inhabitants, ongoing growth is creating shortages on the housing and real estate markets, which tend to counteract the population growth.   * This article belongs to a special issue on reurbanisation

Urban Population Development in Germany (2000-2014): the Contribution of Migration by Age and Citizenship to Reurbanisation

The increase of the population of large German cities between 2000 and 2014 indicates a reurbanisation process in line with the concept of the "growing city". This exploratory investigation will analyse the influence of internal and external migration on the population development of the German urban system by applying descriptive and statistical methods, going beyond the mere observation of selected cities. This paper shows that reurbanisation in Germany has resulted from various age- and citizenship-dependent combinations of spatial population movements, which in turn express different location advantages and disadvantages. The structural change towards a knowledge economy, the expansion of education, and changing living concepts on the demand versus new urbanistic planning concepts on the supply side strengthen the affinity of different population groups for urban living. This new attractiveness of cities seems to be most distinct among young adults’ motives for living in cities or not. Furthermore, the dynamics of these processes are also dependent upon conditions on the national and international levels. Thus, before the economic and financial crisis 2009 the balances of internal migration of the German as well as foreign population had a decisive influence on the dynamics, in-migration surpluses from abroad rose considerably after 2009. With the rising numbers of asylum seekers, state-controlled residence allocations as well as migrant networks are increasingly important for the population development of cities. At the same time, especially in cities with at least 500,000 inhabitants, ongoing growth is creating shortages on the housing and real estate markets, which tend to counteract the population growth

Europas attraktivste Metropolen für Manager : Mannheimer Metropolen-Monitor; Forschungsbericht für das Manager-Magazin

Die vorliegende Studie untersucht die Lebensqualität für ausgewählte europäische Städte, die Arbeitsorte für Manager sein können. Welche sind unter verschiedenen Gesichtspunkten besonders attraktiv, und welche Perspektiven bestehen dort

Efficient Computer Simulation of Polymer Conformation. I. Geometric Properties of the Hard-Sphere Model

A system of efficient computer programs has been developed for simulating the conformations of macromolecules. The conformation of an individual polymer is defined as a point in conformation space, whose mutually orthogonal axes represent the successive dihedral angles of the backbone chain. The statistical-mechanical average of any property is obtained as the usual configuration integral over this space. A Monte Carlo method for estimating averages is used because of the impossibility of direct numerical integration. Monte Carlo corresponds to the execution of a Markoffian random walk of a representative point through the conformation space. Unlike many previous Monte Carlo studies of polymers, which sample conformation space indiscriminately, importance sampling increases efficiency because selection of new polymers is biased to reflect their Boltzmann probabilities in the canonical ensemble, leading to reduction of sampling variance and hence to greater accuracy! in given computing time. The simulation is illustrated in detail. Overall running time is proportional to n^(5/4), where n is the chain length. Results are presented for a hard-sphere linear polymer of n atoms, with free dihedral rotation, with n = 20-298. The fraction of polymers accepted in the importance sampling scheme, fA, is fit to a Fisher-Sykes attrition relation, giving an effective attrition constant of zero. fA is itself an upper bound to the partition function, Q, relative to the unrestricted walk. The mean-squared end-to-end distance and radius of gyration exhibit the expected exponential dependence, but with exponent for the radius of gyration significantly greater than that of the end-to-end distance. The 90% confidence limits calculated for both exponents did not include either 6/5 or 4/3, the lattice and zero-order perturbation values, respectively. A self-correcting scheme for generating coordinates free of roundoff error is given in an Appendix

Computer Simulation of Polymer Conformation. II. Distribution Function for Polymers with Excluded Volume

Numerical distributions of end-to-end distances were generated by a Monte Carlo method for hard-sphere off-lattice polymers of length N = 20, 40, 60, 80, 98, and 298 atoms. Comparison by xz tests against five recently proposed theoretical distribution functions showed that for N = 80 and N = 98, the data could be described, with 95% confidence, by the equation f(r) = exp[ -(ar2 + br + c)], where a and b are fitted parameters and c is a normalization constant. For N = 298, limitations of sample size lead to lower confidence limits (about 80%), but good fit. The above equation, and not its gaussian counterpart exp( -cr^2), is probably the limiting distribution function. The function accurately predicts the 1st through 12th observed moments at all chain lengths

Räumliche Auswirkungen internationaler Migration (2000-2014)

Von 2000 bis 2014 betrug der Außenwanderungsgewinn Deutschlands etwa 2,7 Mio. Menschen. In diesem Zeitraum sind zwei Phasen mit unterschiedlicher Dynamik der internationalen Migration zu erkennen: Im ersten Zeitraum bis 2009 haben sich die jährlichen Salden kontinuierlich verringert und verzeichneten für 2008 wie 2009 sogar leicht negative Werte. Seitdem haben sich die Überschüsse bis 2014 auf über 500 000 Personen erhöht. Diese Änderungen legen nahe, dass sich die Auswirkungen der Außenwanderungen auf die regionale Entwicklung der ausländischen Bevölkerung in den beiden Phasen deutlich unterscheiden

Demografischer Wandel

Der demografische Wandel beeinflusst in hohem Maße die gesellschaftliche Entwicklung in Deutschland. Aus räumlicher Perspektive stehen die Gleichwertigkeit der Lebensverhältnisse und damit die Sicherung der Daseinsvorsorge im Vordergrund. Ihre Gewährleistung erfordert aufgrund der tief greifenden räumlichen Unterschiede im Hinblick auf die Folgen des demografischen Wandels standortspezifische Handlungsansätze

Tendenzen der räumlich-demographischen Entwicklung

Zunächst werden die Teilprozesse des demographischen Wandels vorgestellt. Um dessen räumliche Vielfalt zu erkennen, folgt eine Klassifikation der Raumordnungsregionen. Sie ist das Ergebnis einer Hauptkomponentenanalyse mit anschließendem Clusterverfahren auf der Basis von neun ausgewählten Variablen, welche die Teilprozesse des demographischen Wandels widerspiegeln. Die zukünftige Bevölkerungsdynamik in den Typen verläuft nur bedingt entlang siedlungsstruktureller Kategorien und hebt den Einfluss von nicht demographischen Faktoren auf die Entwicklung der Einwohnerzahlen und der Alterung hervor. In Frankreich und Spanien sind trotz demographischer und sozio-kultureller Unterschiede vergleichbare regionale Trends zu erkennen. Abschließend werden regional spezifische Herausforderungen skizziert und es wird auf die kleinräumige Differenzierung demographischer Probleme verwiesen.The article begins with a presentation of the sub-processes of demographic change, followed - in order to demonstrate its diversity from a spatial perspective - by a classification of spatial planning regions. This classification is the result of a major-component analysis, with a subsequent clustering procedure based on nine variables selected to reflect the sub-processes of demographic change. Only to a limited extent does the future dynamic for population develop in line with settlement-structure categories; this underlines the influence of non-demographic factors on the development of population numbers and on ageing. Despite both demographic and socio-cultural differences, comparable regional trends are recognisable also in France and Spain. The article concludes with an outline of regionally specific challenges, and by pointing to differences in the demographic problems found at the local level from locality to locality

Efficient Computation of Polymer Conformation Energy

Calculation of intramolecular energy of a polymer due to interactions of non-bonded atoms can be speeded up using simple geometric inequalities. This "zippering" method reduces time dependence of computation from n^2 to n^1.25, where n is the chain length. This technique is especially useful in applications of the pivot algorithm