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修勻與小區域人口之研究 / A Study of smoothing methods for small area population金碩, Jin, Shuoh Unknown Date (has links)
由於誤差與人口數成反比,資料多寡影響統計分析的穩定性及可靠性,因此常用於推估大區域人口的方法,往往無法直接套用至縣市及其以下層級,尤其當小區域內部地理、社會或經濟的異質性偏高時,人口推估將更為棘手。本文以兩個面向對臺灣小區域人口進行探討:其一、臺灣人口結構漸趨老化,勢必牽動政府政策與資源分配,且臺灣各縣市的人口老化速度不一,有必要針對各地特性發展適當的小區域人口推估方法;其二、因為壽命延長,全球皆面臨長壽風險(Longevity Risk)的挑戰,包括政府退休金制度規劃、壽險保費釐定等,由於臺灣各地死亡率變化不盡相同,發展小區域死亡率模型也是迫切課題。
小區域推估面臨的問題大致可歸納為四個方向:「資料品質」、「地區人數」、「資料年數」與「推估年數」,資料品質有賴資料庫與制度的建立,關於後三個問題,本文引進修勻(Smoothing, Graduation)等方法來提高小區域推估及小區域死亡模型的穩定性。人口推估方面結合修勻與區塊拔靴法(Block Bootstrap),死亡率模型的建構則將修勻加入Lee-Carter與Age-Period-Cohort模型。由於小區域人口數較少,本文透過標準死亡比(Standard Mortality Ratio)及大區域與小區域間的連貫(Coherence),將大區域的訊息加入小區域,降低因為地區人數較少引起的震盪。
小區域推估通常可用的資料時間較短,未來推估結果的震盪也較大,本文針對需要過去幾年資料,以及未來可推估年數等因素進行研究,希冀結果可提供臺灣各地方政府的推估參考。研究發現,參考大區域訊息有穩定推估的效果,修勻有助於降低推估誤差;另外,在小區域推估中,如有過去十五年資料可獲得較可靠的推估結果,而未來推估年數盡量不超過二十年,若地區人數過少則建議合併其他區域增加資料量後再行推估;先經過修勻而得出的死亡率模型,其效果和較為複雜的連貫模型修正相當。 / The population size plays a very important role in statistical estimation, and it is difficult to derive a reliable estimation for small areas. The estimation is even more difficult if the geographic and social attributes within the small areas vary widely. However, although the population aging and longevity risk are common phenomenon in the world, the problem is not the same for different countries. The aim of this study is to explore the population projection and mortality models for small areas, with the consideration of the small area’s distinguishing characteristic.
The difficulties for small area population projection can be attributed into four directions: data quality, population size, number of base years, and projection horizon. The data quality is beyond the discussion of this study and the main focus shall be laid on the other three issues. The smoothing methods and coherent models will be applied to improve the stability and accuracy of small area estimation. In the study, the block bootstrap and the smoothing methods are combined to project the population to the small areas in Taiwan. Besides, the Lee-Cater and the age-period-cohort model are extended by the smoothing and coherent methods.
We found that the smoothing methods can reduce the fluctuation of estimation and projection in general, and the improvement is especially noticeable for areas with smaller population sizes. To obtain a reliable population projection for small areas, we suggest using at least fifteen-year of historical data for projection and a projection horizon not more than twenty years. Also, for developing mortality models for small areas, we found that the smoothing methods have similar effects than those methods using more complicated models, such as the coherent models.
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小區域人口推估研究:臺北市、雲嘉兩縣、澎湖縣的實證研究 / A study of small area population projection in Taiwan陳政勳 Unknown Date (has links)
一個國家對全國人口有充分瞭解,方能依據國情制定適合的政策,地方發展更是如此,更須洞悉各地的人口結構,以善用有限的資源。台灣近年人口老化日益明顯,各縣市的老化速度及人口問題也不盡相同,若可獲得各地區未來的人口相關數值 (亦即人口推估),當能減輕未來人口老化對台灣造成的衝擊。本文以縣市層級的人口推估,也就是小區域人口推估為研究目標,探討需注意的事項,尋找適合台灣地區的小區域推估方法。
本文整理小區域人口推估方法,並使用人口要素變動合成法 (Cohort Component Method),以雲嘉兩縣、臺北市、澎湖縣為範例,測試縣市層級的人口推估。人口推估與生育、死亡、遷移三者的假設有密切關係,我們以死亡率為目標,比較不同模型的優劣,考慮的模型包括 Lee-Carter 模型、區塊拔靴法 (Block Bootstrap)、篩網拔靴法 (Sieve Bootstrap) 以及泛函資料分析 (Functional Data Analysis) 中的主成份分析 (Principle Component Analysis),以估計誤差為衡量方法優劣的標準。分析發現篩網拔靴法、區塊拔靴法、Lee-Carter 模型三者的結果較佳,因此在小區域推估中使用較簡便的區塊拔靴法。研究發現對小區域的人口推估而言,遷移假設扮演非常重要的角色,此與全國規模的人口推估結果截然不同。研究過程亦發現人口三要素對人口推估有明顯的影響,若假設三要素間互相獨立 (也就是傳統推估時的假設),推估結果的預測區間遠小於三要素不獨立。 / The government can make policy according to the population change in this country, while the local government can develop their district by using their limited resources well after realizing the populaton structure. The population ageing is becoming more serious and being more different among every counties in Taiwan day by day. If we can get the relative numbers of population in the future (population projection), we can decrease the attack of population ageing for Taiwan. The aim of this paper is to find an appropriate method and some notations of small area population projection in Taiwan.
The paper includes the summary of methods of small area population projection and the results by using cohort component method on three areas in Taiwan, YunLin & ChiaYi, Taipein City and PengHu. Population projection is highly related with birth, death and migration, hence we test the mortality rate by using several methods, Lee-Carter, block bootstrap, sieve bootstrap and principal component analysis of functional data analysis are included. We found that the result of sieve bootstrap, block bootstrap and Lee-Carter are much better than the others, therefore, we take block bootstrap which is much simpler than the other two to analysis the effect of birth, death and migration in population projection. The sutdy found that, in small area population projecton, migration plays an important role, which is totally different from the whole country population projection.
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臺灣地區的人口推估研究 / The study of population projection: a case study in Taiwan area黃意萍 Unknown Date (has links)
台灣地區的人口隨著生育率及死亡率的雙重下降而呈現快速老化,其中生育率的降低影響尤為顯著。民國50年時,台灣平均每位婦女生育5.58個小孩,到了民國70年卻只生育1.67個小孩,去年(民國90年)生育率更創歷年新低,只有1.4。死亡率的下降可由平均壽命的延長看出,民國75年時男性為70.97歲,女性為75.88歲;到了民國90年,男性延長到72.75歲,女性延長到78.49歲。由於生育率的變化幅度高於死亡率,對人口結構的影響較大,因此本文分成兩個部份,主要在研究台灣地區15至49歲婦女生育率的變化趨勢,再將研究結果用於台灣地區未來人口總數及其結構的預測。
本研究第一部分是生育率的研究,引進Gamma函數、Gompertz函數、Lee-Carter法三種模型及單一年齡組個別估計法,以民國40年至84年(西元1951年至1995年)的資料為基礎,民國85年至89年(西元1996年至2000年)資料為檢測樣本,比較模型的優劣,尋求較適合台灣地區生育率的模型,再以最合適的模型預測民國91年至140年(西元2002年至2051年)的生育率。第二部分是人口推估,採用人口變動要素合成方法(Cohort Component Projection Method)推估台灣地區未來50年的人口總數及其結構,其中生育率採用上述最適合台灣地區的模型、死亡率則引進國外知名的Lee-Carter法及SOA法(Society of Actuaries),探討人口結構,並與人力規劃處的結果比較之。 / Both the fertility rate and mortality rate have been experiencing dramatic decreases in recent years. As a result, the population aging has become one of the major concerns in Taiwan area, and the proportion of the elderly (age 65 and over) increases promptly from 2.6% in 1965 to 8.8% in 2001. The decrease of fertility rate is especially significant. For example, the total fertility rate was 5.58 in 1961, and then decreases dramatically to 1.67 in 1981 (1.4 in 2001), a reduction of almost 70% within 20 years.
The goal of this paper is to study the population aging in Taiwan area, in particular, the fertility pattern. The first part of this paper is to explore the fertility models and decide which model is the most suitable based on age-fertility fertility rates in Taiwan. The models considered are Gamma function, Gompertz function, Lee-Carter method and individual group estimation. We use the data from 1951 to 1995 as pilot data and 1996 to 2000 as test data to judge which model fit well. The second part of this study is to project the Taiwan population for the next 50 years, i.e. 2002-2051. The projection method used is Cohort Component Projection method, assuming the population in Taiwan area is closed. We also compare our projection result to that by Council for Economic Planning and Development, the Executive Yuan of the Republic of China.
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Populační vývoj ve Švédsku od roku 1960 / Population development in Sweden since 1960Nováková, Iveta January 2021 (has links)
Population development in Sweden since 1960 Abstract This diploma thesis deals with the population development in Sweden between 1960 and 2018. The main goal of this work is to evaluate in the context of selected demographic characteristics the course of demographic changes that appeared in the country after 1960. The result is changes in the level of demographic reproduction, which are referred to as the second demographic transition. From the 1960s to the present, Sweden has seen an increase in the average age at first marriage, an increase in the average age of the mother giving birth and an increase in the number of divorces. During the observed period, the Swedish population aged, the share of the pre-productive component of the population decreased, while the share of the post-productive component in the population increased. The development of total fertility in Sweden is often compared to a roller coaster due to its specific fluctuation. From 1960 to 2018, Sweden saw a decline in mortality rates, especially in the older age groups and up to one year of age, which was reflected in the values of life expectancy at birth that grew for both men and women. Sweden is inspiring for other European countries with its gender-neutral family and social policy. Keywords: population development, Sweden, second...
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