1,561 research outputs found

    The economic impact of demographic structure in OECD countries

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    We examine the impact of demographic structure, the proportion of the population in each age group, on growth, savings, investment, hours, interest rates and inflation using a panel VAR estimated from data for 20 OECD economies, mainly for the period 1970-2007. This flexible dynamic structure with interactions among the main macroeconomic variables allows us to estimate long-run effects of demographic structure on the individual countries. Our estimates confirm the importance of these effects

    Demografie bremst Wirtschaft

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    Wie beeinflusst die Demografie das Wirtschaftswachstum in den Industriestaaten? Während junge und alte Menschen einen negativen Einfluss haben, ist der Effekt bei der Gruppe im arbeitsfähigen Alter positiv. In einer Studie aus dem Jahr 2015 wurde ein theoretisches Modell entwickelt, um den Zusammenhang zwischen Demografie, Innovation und BIP-Wachstum anhand von empirischen Daten aufzuzeigen. Dabei zeigt sich: Die zunehmende Alterung und die tiefen Geburtenraten beeinflussen das Produktionswachstum und die Realzinsen negativ. An diesem Szenario dürfte sich in den nächsten Jahren wenig ändern

    Medium-run implications of changing demographic structures for the macro-economy

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    While there may be an important, but transitory, cyclical component in the poor performance of the past decade, we will emphasise the secular forces: the impact of demographic structure and innovation. We draw on the empirical and theoretical work reported in Aksoy, Basso, Smith and Grasl (2015), ABSG, about the impact of changes in demographic structure on macroeconomic outcomes. This suggests that changes in age profile not only have significant implications for savings, investment, real interest rates and growth but also for innovation. The size of the effects seems plausible. For instance, if in 2015 the UK had the 1970 age structure, it would have added 0.68 percentage points to the long-run annual growth rate. The model suggests that the population ageing predicted for the next decades will tend to reduce output growth and real interest rates across OECD countries

    Demographic structure and macroeconomic trends

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    We analyse both empirically and theoretically the effects of changes in demographic structure on the macroeconomy, looking particular at their impact to medium-term trends. Our empirical exercise examines the impact of the proportion of the population in each age group, on growth, savings, investment, hours, interest rates and inflation using a panel VAR estimated from data for 20 OECD economies for the period 1970-2007. This flexible dynamic structure with interactions among the main variables allows us to estimate both the direct impact of demographic structure and their feedback effects. Our estimates confirm the importance of age structure, with young and old dependants having a negative impact on most macroeconomic variables while workers contribute positively. Our theoretical framework incorporates demographic heterogeneity and endogenous productivity, allowing us to study the medium-term interaction of demographic changes and savings, investment, and innovation decisions. Theoretical simulations incorporating the changes in demographic structure experienced by many OECD countries in the past decades replicate well our empirical findings. The current trend of population aging and reduced fertility, expected to continue in the next decades, is found to be a strong force in reducing output growth and real interest rates across OECD countries

    Demographic structure and macroeconomic trends

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    We estimate the effect of changes in demographic structure on long term trends of key macroeconomic variables using a Panel VAR for 21 OECD economies from 1970-2014. The panel data variation assists the identification of demographic effects, while the dynamic structure, incorporating multiple channels of influence, uncovers long-term effects. We propose a theoretical model, relating demographics, innovation and growth, whose simulations match our empirical findings. The current trend of population ageing and low fertility is projected to reduce output growth, investment and real interest rates across OECD countries

    Development of a near-wall Reynolds-stress closure based on the SSG model for the pressure strain

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    In this research, a near-wall second-order closure based on the Speziable et al.(1991) or SSG model for the pressure-strain term is proposed. Unlike the LRR model, the SSG model is quasi-nonlinear and yields better results when applied to calculate rotating homogeneous turbulent flows. An asymptotic analysis near the wall is applied to both the exact and modeled, equations so that appropriate near-wall corrections to the SSG model and the modeled dissipation-rate equation can be derived to satisfy the physical wall boundary conditions as well as the asymptotic near-wall behavior of the exact equations. Two additional model constants are introduced and they are determined by calibrating against one set of near-wall channel flow data. Once determined, their values are found to remain constant irrespective of the type of flow examined. The resultant model is used to calculate simple turbulent flows, near separating turbulent flows, complex turbulent flows and compressible turbulent flows with a freestream Mach number as high as 10. In all the flow cases investigated, the calculated results are in good agreement with data. This new near-wall model is less ad hoc, physically and mathematically more sound and eliminates the empiricism introduced by Zhang. Therefore, it is quite general, as demonstrated by the good agreement achieved with measurements covering a wide range of Reynolds numbers and Mach numbers

    Antenatal screening and its possible meaning from unborn baby's perspective

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    In recent decades antenatal screening has become one of the most routine procedure of pregnancy-follow up and the subject of hot debate in bioethics circles. In this paper the rationale behind doing antenatal screening and the actual and potential problems that it may cause will be discussed. The paper will examine the issue from the point of wiew of parents, health care professionals and, most importantly, the child-to-be. It will show how unthoughtfully antenatal screening is performed and how pregnancy is treated almost as a disease just since the emergence of antenatal screening. Genetic screening and ethical problems caused by the procedure will also be addressed and I will suggest that screening is more to do with the interests of others rather than those of the child-to be

    Enhanced radiation damage tolerance of amorphous interphase and grain boundary complexions in Cu-Ta

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    Amorphous interfacial complexions are particularly resistant to radiation damage and have been primarily studied in alloys with good glass-forming ability, yet recent reports suggest that these features can form even in immiscible alloys such as Cu-Ta under irradiation. In this study, the mechanisms of damage production and annihilation due to primary knock-on atom collisions are investigated for amorphous interphase and grain boundaries in a Cu-Ta alloy using atomistic simulations. Amorphous complexions, in particular amorphous interphase complexions that separate Cu and Ta grains, result in less residual defect damage than their ordered counterparts. Stemming from the nanophase chemical separation in this alloy, the amorphous complexions exhibit a highly heterogeneous distribution of atomic excess volume, as compared to a good glass former like Cu-Zr. Complexion thickness, a tunable structural descriptor, plays a vital role in damage resistance. Thicker interfacial films are more damage-tolerant because they alter the defect production rate due to differences in intrinsic displacement threshold energies during the collision cascade. Overall, the findings of this work highlight the importance of interfacial engineering in enhancing the properties of materials operating in radiation-prone environments and the promise of amorphous complexions as particularly radiation damage-tolerant microstructural features

    Assessment of paranasal sinus parameters according to ancient skulls’ gender and age by using cone-beam computed tomography

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    Background: The aim of this study was to determine whether paranasal sinus dimensions and volume can be useful to identify gender and age estimation for ancient skulls using cone-beam computed tomography (CBCT) images.  Materials and methods: CBCT scans of 32 ancient skulls of approximately 1000 years of age were included in this retrospective study. The gender and age estimation of the skulls were made by an independent anthropologist, which was considered as the gold standard. Paranasal sinuses’ dimensions (width and height) and volumes of each sinus were measured from the CBCT data set that was linked to the three-dimensional rendering software (Anatomage, Invivo 5.2). All measurements were performed by an independent observer. Intra-observer analysis was made. Mann-Whitney and Kruskal-Wallis tests were used to compare paranasal sinus parameters in terms of age estimation and gender (p < 0.05).  Results: The results demonstrated no statistically significant difference between measurements (p < 0.05). The measurements were found to be highly reprodu- cible. The mean volumes of frontal and sphenoid sinus were found to be higher in males. The distance from anterior-posterior wall of sphenoid sinus in axial sec- tions is larger in males (p > 0.05). The frontal sinus width and volume increased statistically with age above 60 years of age (p > 0.05).  Conclusions: The paranasal volume and dimensions’ measurements from CBCT data can be a promising technique to determine gender and age of ancient skulls because of its lower voxel sizes and higher resolution.

    Inequality and Procedural Justice in Social Dilemmas

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    This study investigates the influence of resource inequality and the fairness of the allocation procedure of unequal resources on cooperative behavior in social dilemmas. We propose a simple formal behavioral model that incorporates conflicting selfish and social motivations. This model allows us to predict how inequality influences cooperative behavior. Allocation of resources is manipulated by three treatments that vary in terms of procedural justice: allocating resources randomly, based on merit, and based on ascription. As predicted, procedural justice influences cooperation significantly. Moreover, gender is found to be an important factor interacting with the association between procedural justice and cooperative behavior.
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