Mauritius Case Study: Alternative Histories Since 1962

This Working Paper constitutes Chapter 17 of the book manuscript, "Understanding Population-Development-Environment Interactions: A Case Study on Mauritius". The Mauritius case study was carried out by IIASA in scientific collaboration with the University of Mauritius and funded by the United Nations Population Fund (WNFPA). The paper presents and discusses findings from the interdisciplinary computer model simulating alternative population-development-environment interactions for the historical period 1962 to 1987, a period of rapid change in Mauritius. In a first step, population, economic, and environmental developments during the last 30 years are reconstructed by the PDE-Mauritius model on the basis of observed trends. This reconstructed history, which also evaluates the accuracy of the model itself, is used as a reference to which alternative histories are compared. In subsequent sections, five alternative population histories and nine alternative holistic histories are considered. The role of socio-demographic development, and of the fertility decline in particular, is compared to the importance of the economic boom for the rapid development of Mauritius. Also, the influence of specific economic strategies, like agricultural exports (mainly sugar), industrial exports (mainly textiles), or tourism, and in particular their impact on the environment, are investigated

Modeling the Population of Mauritius

Within IIASA's project on "Population and Sustainable Development: A Case Study of Mauritius" an interactive software tool describing the dynamics of population-development-environment interactions was developed. In contrast to similar existing models, population is not only an input variable but it is a driving force of the system. The population module provides the structure of the population by age, sex, level of education and labor force participation. For the future, different levels of fertility, mortality, migration, progression in education and labor force entrance and exit can easily be specified by the user. Changes in those variables in the past have been remarkable. Dependency ratios, calculated in several levels of refinement, show an amazing decline over the period 1962-1990. With different demographic developments, the past three decades would not have brought a significant decline in dependency ratios and may thus possibly have hindered or at least delayed economic development. In the coming decades the population of Mauritius will grow by some 30-40 per cent and it will age considerably. Changes in the socio-demographic composition of the population caused by recent and expected changes in the education and labor force distribution, however, indicate that further economic development is strongly favored during the next two decades

Marital Status and Population Projections

Is marital status a disappearing issue? Reading demographic literature one may get the impression that information on marital status no longer helps to explain demographic phenomena, at least in industrialized countries. The argument is that legal marital status differs strongly from actual living arrangements for, as an example, an increasing number of people prefer to live in a consensual union instead of getting married. The aim of this research is to answer the question whether it is still useful to analyze the populations past and possible future marital status composition. We cannot refuse to believe in the continued increase of non-traditional living arrangements that are a consequence of changing values and attitudes. This, however, does not mean that legal marital status analysis has become obsolete. Analysis for different industrialized countries even demonstrates the opposite. In the recent past, that is the period 1960-1985, changes in the marital composition became increasingly important for explaining various demographic processes. Fertility changes were more and more due to the increase in the proportion of non-married people. Similarly, household changes could more and more be attributed to changes in the marital structure of the population. Both are demonstrated by decomposition analysis. Furthermore, using marital status information for population projections results in significant differences already in the short run. Consequently, when analyzing demographic changes or projecting populations and households, demographers should even now regard legal marital status as one of their main input variables

Evaluating a Pension System Considering Children Born: The Case of Austria

The paper discusses the consequences of the adoption of a new pension system that considers the number of children born in Austria. Combining a demographic family model with a pension model and cost profiles of social security expenditures, a policy simulation tool is obtained which allows the testing of different social security policies. The feasibility of the suggested pension reform is examined on both the system level and the individual level to determine under which circumstances such a policy is reasonable and affordable. The first conclusion is that the new pension system would be cost neutral. Secondly, provided a certain response to the pronatalist character of the new system in the form of an increase in fertility, the performance of the social security system would improve. Thirdly, the new system would significantly change the income distribution of retired women to the extent that single and divorced women with children are no longer discriminated. Thus, the emancipatory goal of the policy is fulfilled

Accuracy of circular polarization as a measure of spin polarization in quantum dot qubits

A quantum dot spin LED provides a test of carrier spin injection into a qubit, as well as a means of analyzing carrier spin injection in general and local spin polarization. The polarization of the observed light is, however, significantly influenced by the dot geometry so the spin may be more polarized than the emitted light would naively suggest. We have calculated carrier polarization-dependent optical matrix elements using 8-band strain-dependent k.p theory for InAs/GaAs self-assembled quantum dots (SAQDs) for electron and hole spin injection into a range of quantum dot sizes and shapes, and for arbitrary emission directions. The observed circular polarization does not depend on whether the injected spin-polarized carriers are electrons or holes, but is strongly influenced by the SAQD geometry and emission direction. Calculations for typical SAQD geometries with emission along [110] show light that is only ~5% circularly polarized for spin states that are 100% polarized along [110]. Therefore observed polarizations [Chye et al. PRB 66, 201301(R)] of ~1% imply a spin polarization within the dot of ~20%. We also find that measuring along the growth direction gives near unity conversion of spin to photon polarization, and is the least sensitive to uncertainties in SAQD geometry.Comment: 4 pages, 6 figure

What Difference Do Alternative Immigration and Integration Levels Make to Western Europe?

The population of Western Europe (EC plus EFTA) is seen as consisting of three subpopulations: the natives, the East-European immigrants, and the non-European immigrants. Different immigration levels assumed from Eastern Europe and from the rest of the world add to the non-native populations while different levels of "integration" describe the transition intensities from the non-native sub-populations to the native category. The paper gives alternative population projections to 2050 based on six scenarios with different assumptions on net migration, "integration", as well as fertility and mortality in the three categories. The results indicate that (i) in the case of no further immigration the total population of Western Europe will start to decline after 2010; (ii) the rate of integration into the native population influences the future size of the non-European population much more than alternative levels of immigration; (iii) in the long run the Eastern Europeans will be quantitatively insignificant; (iv) the Western European population is bound to significant population aging no matter what happens with immigration; and (v) in the short to medium run immigrants contribute to the alleviation of the pension burden

Scenarios for the World Population in the Next Century: Excessive Growth or Extreme Aging

For six major regions of the world, ten alternative scenarios on future fertility and mortality trends are defined and projections performed from the base year 1985 up to the year 2100. Because of the great inertia of population changes, for the next 20-30 years the scenarios based on widely diverging assumptions do not produce very different patterns. In the longer run, however, the assumption of constant fertility and mortality rates resulting in continued exponential growth yields a total population size of 15 billion in 2050 and even 39 billion in 2100. The immediate replacement fertility scenario, on the other hand, would result in 7.5 billion by 2050. This still means an addition of more than two billion people to today's population of 5.3, which is entirely due to the momentum of population growth. Another major finding is that further aging of the population structure is inevitable even under constant rates. In the case of successful curbing of population growth, aging would be extremely rapid. For example, in Africa under the immediate replacement scenario the mean age of the population would increase from presently 22.2 years to more than 40 years by 2050. More moderate scenarios also result in very significant aging

Action comprehension: deriving spatial and functional relations.

A perceived action can be understood only when information about the action carried out and the objects used are taken into account. It was investigated how spatial and functional information contributes to establishing these relations. Participants observed static frames showing a hand wielding an instrument and a potential target object of the action. The 2 elements could either match or mismatch, spatially or functionally. Participants were required to judge only 1 of the 2 relations while ignoring the other. Both irrelevant spatial and functional mismatches affected judgments of the relevant relation. Moreover, the functional relation provided a context for the judgment of the spatial relation but not vice versa. The results are discussed in respect to recent accounts of action understanding

Pension Systems and Social Security: Trends and National Characteristics

This brief survey paper on the main characteristics of pension systems and social security systems in twelve European countries and Canada belongs to a series of papers originating from the project "Family, Household, and Social Security in Aging Societies." It provides a basis for comparing past and probable future trends in the thirteen countries currently participating in the project