1,167 research outputs found
The population of Finland in 2050 and beyond
During the next fifty years, the growth of the population of Finland is expected to slow down, and turn into decline. The age-distribution is expected to become older because mortality declines. In particular, the share of the working age population will decline. This development is accentuated by the fact that the large post war birth cohorts reach retirement age during the next decade. Although there is general agreement about these broad features, it is difficult to say exactly when a decline might begin, or how high the age-dependency ratio will be like in the future. A study of past forecasts shows that demographic developments have repeatedly taken forecasters by surprise. We show that the forecast errors in Finland have not been related to other social phenomena, such as wars or economic crises, in a simple way. In fact, our understanding of the causes of the past errors is poor. Therefore, it is important to recognize that our current view of future population development may similarly be in error. We account for the uncertainty by statistical modeling. In this way it is possible to estimate, how large errors one should expect, if future demographic development is as volatile as in the past. Using stochastic simulation, we derive a predictive distribution for the future population vector that gives a realistic indication of the uncertainty to be expected
A statistical look at Modeen's forecast of the population of Finland in 1934
Gunnar Modeen made the first cohort-component forecast for Finland in 1934. This was a time when demographic transition was just over, but that fact could not have been known at the time. Would it have made any difference if Modeen had had the tools of modern time-series analysis available? We find that the essential question of how to deal with changing trends would have still been difficult. However; the modern tools would have given the forecast user a realistic indicator of the uncertainty of the forecast being made. This suggests that in developing countries that are undergoing transition now, more effort should he paid to the analysis of uncertainty of forecasting
A note on the use of anticipatory covariates in event history analysis
Anticipatory covariates are regressors whose values become known only after the value of the dependent variable has been ascertained. Hoem (1995) has given an informal discussion concerning the possible pitfalls in the use of such covariates in event history analysis. This paper complements Hoem’s findings by using simple linear regression as the framework. It turns out that complex patterns of bias may be introduced by the use of anticipatory covariates. In all cases it may not be possible to guarantee that the magnitude of the bias remains small. Therefore, extreme care is needed in interpreting results from studies that have relied on anticipatory covariates
On finite-temperature holographic QCD in the Veneziano limit
Holographic models in the T=0 universality class of QCD in the limit of large
number N_c of colors and N_f massless fermion flavors, but constant ratio
x_f=N_f/N_c, are analyzed at finite temperature. The models contain a
5-dimensional metric and two scalars, a dilaton sourcing TrF^2 and a tachyon
dual to \bar qq. The phase structure on the T,x_f plane is computed and various
1st order, 2nd order transitions and crossovers with their chiral symmetry
properties are identified. For each x_f, the temperature dependence of p/T^4
and the quark-antiquark -condensate is computed. In the simplest case, we find
that for x_f up to the critical x_c\sim 4 there is a 1st order transition on
which chiral symmetry is broken and the energy density jumps. In the conformal
window x_c<x_f<11/2, there is only a continuous crossover between two conformal
phases. When approaching x_c from below, x_f\to x_c, temperature scales
approach zero as specified by Miransky scaling.Comment: 66 pages, 29 figure
Farm Deaths in North Karelia
This study examined the effect of farm size on the mortality and survival of EasternFinnish farms in the late 1990s. Three different dimensions of farm size (i.e. hectaresoperated, number of milk cows, and hectares of forest) were compared. Data wereextracted from administrative records and covered all 4,527 active farms in NorthKarelia from 1995 to 1998. Results did not support the disappearing middle sizehypothesis presented by Weiss (1999). Farm size distributions were not bimodal.No empirical evidence was found of a process of polarisation into two centres ofattraction. As a whole, the analysis provides some support for the conclusion thatthe size of forest holding as measured by hectares of forest owned by farm does nothave an independent effect on the likelihood of survival. Its contribution dependson the other variables in the model
Assumptions for long-term stochastic population forecasts in 18 European countries: Hypothèses de projections stochastiquesàlong terme des populations de 18 pays européens
The aim of the ‘Uncertain Population of Europe’(UPE) project was to compute long-term stochastic (probabilistic) population forecasts for 18 European countries. We developed a general methodology for constructing predictive distributions for fertility, mortality and migration. The assumptions underlying stochastic population forecasts can be assessed by analysing errors in past forecasts or model-based estimates of forecast errors, or by expert judgement. All three approaches have been used in the project. This article summarizes and discusses the results of the three approaches. It demonstrates how the—sometimes conflicting—results can be synthesized into a consistent set of assumptions about the expected levels and the uncertainty of total fertility rate, life expectancy at birth of men and women, and net migration for 18 European countries
Fiscal sustainability and policy rules: Under changing demographic forecasts
All practical evaluations of fiscal sustainability that include the effects of population ageing must utilize demographic forecasts. It is well known that such forecasts are uncertain, and that has been taken into account in some studies by using stochastic population projections jointly with economic models. We develop this approach further by introducing regular demographic forecast revisions that are embedded in stochastic population projections. This allows us to separate systematically, in each demographic outcome and under different policy rules, the expected and the actualized effects of population ageing on public finances. We show that the likelihood of sustainability risks is significant, and that it would be wise to consider policies that reduce the likelihood of getting highly indebted. Furthermore, although demographic forecasts are uncertain, they seem to contain enough information to be useful in forward-looking policy rules
Contaminação por mercúrio em sedimento e moluscos da Bacia do rio Bento Gomes, MT.
Os níveis de mercúrio total detectados no sedimento e tecidos moles de moluscos gastrópodos provenientes da bacia hidrográfica do rio Bento Gomes, embora baixos, mostraram indícios de contaminação. De um total de 69 amostras de sedimento analisadas, 26% apresentaram níveis de mercúrio total variando de 0,01 a 0,25 µg.g-1 de mercúrio (peso úmido). Os níveis de mercúrio obtidos em 54 amostras dos moluscos Ampullaria scalaris; A. canaliculata e Marisa planogira evidenciaram que 39% estavam contaminadas com níveis variando de 0,02 a 1,6 µg.g-1 de peso úmido. Estes resultados indicam que o mercúrio utilizado na extração de ouro de aluvião está atingindo o ambiente aquático e contaminado o sedimento e os organismos bentônicos desta área do Pantanal.bitstream/item/37304/1/BP58.pd
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