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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

控制風險值下的最適投資組合

洪幸資 Unknown Date (has links)
採用風險值取代標準差來衡量投資組合的下方風險,除了更符合投資人的對風險的態度,也更貼近目前金融機構多以風險值作為內部控管工具的情形。但除了風險的事後衡量,本篇論文希望能夠事前積極地控制投資組合風險值,求得最適投資組合的各資產配置權重。故本篇論文研究方法採用了Rockafellar and Uryasev.(2000)的極小條件風險值最適投資組合模型先建立Mean-CVaR效率前緣,並將此效率前緣上的投資組合風險以風險值衡量,再應用電腦上的探索方法進一步求得風險值更低的投資組合,逼近求得Mean-VaR效率前緣,最後利用Mean-VaR效率前緣採用Campbell,Huisman與Koedijk(2001)模型求得控制風險值下的最適投資組合。 在實證分析上,本篇論文採用國內三檔股票為標的,首先在實證標的資產報酬檢定為非常態分配下,使用歷史模擬法,以資產實際非常態報酬分配估計VaR,驗證了使用本篇論文研究方法極小CVaR投資組合與探索方法,可以適當逼近真實的Mean-VaR效率前緣。再者研究比較不同信賴水準、不同資產報酬分配假設與不同權重產生方式下的Mean-VaR效率前緣與Mean- 效率前緣效果差異,最後求得控制風險值下的最適投資組合。 / In contrast to the role of variance in the traditional Mean-Variance framework, in this thesis we introduce Value-at-Risk (VaR) as a shortfall-constraint into the portfolio selection decision. Doing so is much more in fitting with individual perception to risk and in line with the constraints which financial institutes currently face. However, mathematically VaR has some serious limitations making the portfolio selection problem difficult to attain optimal solution. In order to apply VaR to ex ante portfolio decision, we use the closely related tractable risk measure Conditional Value-at-Risk (CVaR) in this thesis as a proxy to find efficient portfolios. We utilize linear programming formulation developed by Rockafellar and Uryasev(2000) to construct a Mean-CVaR efficient frontier. Following which the VaR of resulting portfolios in the Mean-CVaR efficient frontier is reduced further by a simple heuristic procedure. After constructing an empirical Mean-VaR efficient frontier that can be proven an useful approximation to the true Mean-VaR efficient frontier, the Campbell, Huisman and Koedijk(2001) model is used to find the optimal portfolio. Three Taiwan listing stocks are used to build the Mean-VaR efficient frontier in the empirical study. And the Mean-VaR efficient frontier of different confident levels, under different asset return assumptions, and different optimal portfolio selection models are compared and results analyzed.
2

壽險業資金運用效率與國外投資額度關係之研究

林金樹 Unknown Date (has links)
由於市場利率持續低迷,壽險業利差損問題成為關切焦點,而國內金融市場投資工具仍然有限,壽險業2004年底5兆1,126億元的可運用資金總額中,有6,115億元(占可運用資金12.3%)投資於銀行存款及商業本票等短期投資部位。無論監理機關或壽險業均將解決之道,寄望於提高國外投資上限。本次保險法修正草案中,亦建議提高國外投資上限至資金之50%。 本研究嘗試透過計算壽險業有效契約平均預定利率、分析台灣現行金融環境下壽險業資產配置之困境,據以探討提高國外投資上限至50%,能否解決壽險業所面臨之經營困境,並提出建議做法,期能有助提供相關單位之參考。 本研究發現,壽險業有效契約平均預定利率,雖然隨著新契約預定利率逐漸調降而降低,但各項法定資金運用管道,在現行台灣整體金融環境下,很難達到損益兩平。 由風險性資產效率前緣分析也發現,國外投資上限之提高在避險成本較低時,不失為在台灣金融工具之質與量無法短期提升下,業者可以提高資金運用收益之解決方案。但如果避險成本增加,隨著國外投資上限提高而將資金移往國外,投資效率並不見得會提升,但卻也不會比提高前來得差,此時投資效率,將端視個別公司風險控管及國外金融工具選擇能力而定。 所以提高國外投資上限,僅能視個別公司逐案嚴加審核,甚至超出現行35%上限部分,應比現行審核標準更嚴格,無法通案為之。重要的是,政府要提出改善金融環境及健全保險業發展之整體策略,而不是僅僅著眼於提高國外投資上限。 關鍵字:國外投資、有效契約平均預定利率、效率前緣 / Because the environment of low interest rate, Life Insurance company’s loss expanded and raised the concerns of investors. More badly, the domestic high-yield-rate investment tools are less. For example, the total disposable capitals reached NT$ 5,112 billions in the end of 2004. There are 12.3% of these huge bucks, i.e. NT$ 611 billions that put in short term investment including commercial papers and cash. Now, not only the authorities also the life insurers are expecting the augment of foreign investment percentage. Recent amendments on the Law of Insurance suggest raise the ceiling of foreign investment from 35% to 50%. In order to propose total solutions for life insurers and MOF, this paper goes through broad discussions on 「Could the augment of investment ceiling solve the issues of interest loss?」 Hopefully, the life insurers would benefit from them. And these topics are 「the calculation of assumed interest rate of in-force life insurance policies」、「the analysis of Taiwan life insurers’ dilemma for assets management in current financial environment」. This paper advises that break-even normally is very difficult in Taiwan financial environment currently. Although the industrial average assumed interest rate of in-force policies is decreasing due to the lower assumed interest rate of new contracts. The legal investment tools are still far too less. Low yield rate and duration mismatch are the aches deep in the heart of life insurers. Due to the shortage of investment tools, the efficiency frontier analysis suggests that life insurers shall enhance oversea investment as a total solution. And it will create expected returns under the low cost of hedge. Nevertheless, if the hedging cost is uprising, the results of expanding oversea investment won’t create values any more. By the way, it won’t perform worse either if life insurers uphold original investment decision. Actually, the results of investment depend on risk management and the ability to choose better oversea investment tools. To conclude that the augment of oversea investment ceiling could be approved case-by-case not to enact the law. Especially the part exceeding 35% should be audited more toughly. The augment of oversea investment ceiling is not the key issue. More important is that the government shall propose national strategy to improve financial environment and build up sound development settings for insurance industry. Key Words:Oversea Investment、Assumed Interest Rate of In-force Policies、Efficiency Frontier
3

一籃子貨幣避險

陳盈吟, Chen, Ying Ying Unknown Date (has links)
近年來因國內利率持續走低,壽險公司紛紛至海外尋找收益更佳的投資機會與標的,其中大部份以固定利率的海外資產為主。這些海外的投資部位,雖然讓壽險公司享受到較國內金融資產高的投資名目收益,但在投資期間結束後,壽險公司仍面臨必需以新台幣結算投資損益的不確定性。因此,壽險公司進行匯率避險成為海外投資組合中最關鍵的一環。為達到規避匯率風險以及降低避險成本這兩個目的,一籃子貨幣組合避險策略(A BASKET OF MONEY HEDGE STRATEGE)因此被發展出來。 1. 希望能夠提供海外投資者另一種規避新台幣匯率風險的方法。 2. 瞭解各種不同的貨幣篩選方法可能存在何種差異性。 3. 根據實證結果提出適當建議,以供後續研究者參考。 本研究首先選取一些目標貨幣當作一籃子貨幣的基準貨幣,為使整個避險投資組合的效果提升,必需考慮各種幣別與台幣的替代性是否夠高,所以利用以下各項因子來作為貨幣篩選的標準,如:各幣別與台幣之相關性、各幣別與美元的利差、替代貨幣本身的波動性、各替代貨幣間之相關性等因素進行替代貨幣的篩選機制。 / 利用以上要點篩選出基準貨幣後,再利用Markowitz所提出之效率前緣分析方式來選擇最適合的貨幣配置。就是在給定投資組合部位限制下,給定期望報酬使總風險為最小之配置比重,即為最佳化投資組合。利用Matlab之指令portopt給定歷史報酬及共變異數矩陣,即可輕易求出效率前緣曲線,以及最佳化貨幣配置比率,再與傳統之避險方式做比較,以求取更佳的一籃子避險策略。
4

熵風險值約當測度的動態資產組合理論及實證研究 / Dynamic Portfolio Theory and Empirical Research Based on EVaR Equivalent Measure

張佳誠 Unknown Date (has links)
在資產組合的優化過程中,總是希望賺取穩定的報酬以及規避不必要的風險,也因此,風險的衡量在資產組合理論中至關重要,而A. Ahmadi-Javid(2011)發表證明以相對熵為基礎的熵風險值(Entropic Value-at-Risk,簡稱EVaR)是為被廣泛使用的條件風險值(Conditional Value-at-Risk,簡稱CVaR)之上界,且EVaR在使用上更為效率,具有相當優越的性質,而本文將利用熵風險值的約當測度,去修改傳統均值–變異模型,並以臺灣股市為例,利用基因模擬退火混合演算法來驗證其在動態架構下的性質及績效,結果顯示比起傳統模型更為貼近效率前緣。
5

退休基金之最適資產配置與風險管理探討─勞工保險基金實證分析

陳冠宏, Chen, Guan-Homg Unknown Date (has links)
本研究針對國內勞工保險基金進行最適資產配置與風險管理之實證研究。首先以效率前緣法分析勞保基金最適配置,發現目前基金配置並沒有在效率前緣線上,因此建議勞保基金進行配置之調整。此外利用蒙地卡羅以及歷史資料模擬法進行勞保基金清償能力分析,發現在目前法規限制下,需將費率調高到9%時才能確保未來基金50年有90%的機率不會破產。又費率9%之下5種配置都可達到100%不會破產,因此配置可選擇風險最小之組合作為最適配置。若考慮放寬投資限制,則將費率調高至8.5%時有4種配置可達到上述之要求,此時可選擇不破產機率最高的組合,即報酬率9%下之配置作為最適配置。 接著本文利用風險值(Value at Risk)對勞保金進行風險管理,風險值分析可知國內股票與國外有價證券是主要的風險值來源,在信心水準95%和99%之下,利用三種方法所計算風險值約118億以及181億元。若某一資產損失金額超過其個別風險值貢獻時,管理者應立即監控且通報上層主管,必要時改變資產投資內容,降低其風險。一旦損失金額超過總體風險值時,就需要改變基金的配置比例,減少整體風險,直到基金的風險降低到可允許的範圍之內。降低風險值方面可以利用邊際風險值進行調整,若風險值超過可容忍範圍時,可增加邊際風險值為負值的資產類別比重來降低風險值,同時應注意基金之整體報酬率會因此下降,是否能維持基金清償能力須再一次進行評估,如果無法達到要求時,最佳的方法為尋找品質更佳之資產,即報酬率高但是風險相對來說較低之標的,因此在投資標的之選擇就很重要,而選擇的方法也考驗著基金管理者的功力。
6

保險法中股票投資限制與估計風險之探討

郭榮堅, Kuo, Jung-Ching Unknown Date (has links)
假設真實輸入參數可以事先預知,實際上,透過平均數-變異數的投資組合量化模式,效率前緣將會往右下方移動。這也意謂倘若保險公司的投資策略有達到效率前緣的情況下,保險法146條的投資上限將使得保險公司的投資報酬率降低,以及投資風險增加。給定投資上限反而降低保險公司的投資績效。然而真實輸入參數並無法事先預知,因此根據過去的經驗資料以及主觀判斷來估計輸入參數將是作為取代真實參數的作法。而估計誤差的存在將勢難避免。同時平均數-變異數模式所決定的投資組合會過度投資在高估投資報酬率以及低估投資風險的股票上,因此估計誤差的影響將是不容忽略。並且保險公司在追求資產極大化的同時,有其必要兼顧到估計誤差的影響。 本研究主要有三個主題,首先我們透過平均數-變異數模式來探討估計誤差對投資組合的影響。緊接著就投資上限與估計風險的關係進行研究。最後分析股票淨利率限制和投資上限之間的關係,並且解釋存在的功能以及探討是否有其存在的必要性。 本研究結果發現現行的單一股票的投資上限(七分之一)不但降低了投資風險,並且改善了真實反應的投資報酬率低於6%,甚至為負值的問題。並且就淨利率上限為6%的合適性而言,除非保險公司採取的投資策略非常的保守,否則還不如放寬,或者廢除。
7

兩岸傳統產業公司治理與經營績效關聯性比較 / Corporate governance and operating efficiency performance: a comparison of traditional industry between Taiwan and China

古秀敏, Ku, Hsiu-Ming Unknown Date (has links)
本研究欲探討兩岸傳統產業公司治理與經營績效之關聯性,運用資料包絡分析法及Cummins, Weiss和Zi (1999)之交叉效率前緣評估比較2005至2009年兩岸公司之經營績效差異。並進一步採用縱橫資料迴歸模型分析兩岸傳統產業之公司治理機制與經營績效之關聯。 根據本研究實證結果顯示:首先,兩岸傳統產業分屬不同效率前緣,且大陸傳統產業之技術效率優於台灣傳統產業之技術效率。說明台灣傳統產業雖較中國傳統產業發展的時間點為早,不過由於台灣之傳統產業屬於早期赴中國投資的先驅,當時已將核心技術帶入中國,近年來中國傳統產業因內需龐大加上國家支持而發展迅速,無論在規模或產值上都遠遠超過台灣。而在公司治理機制中,大陸傳統產業公司國內機構法人持股率及國有股比例與其經營績效呈顯著顯著負向關係,和其他研究結果一致,而經理人持股率、國外機構法人持股率與獨立董事比例則與經營績效無顯著關聯;台灣傳統產業公司經理人持股率、國內機構法人持股率、國外機構法人持股率、董事淨持股率及獨立董事比例與公司之經營皆無顯著關聯。敏感性分析顯示與上述結果類似。 / The purpose of this paper is to examine and compare the relationship between corporate governance and efficiency performance of traditional industry(TI) in Taiwan and China. We apply data envelopment analysis and cross frointer analysis to measure and compare the performance difference between Taiwan and China. The research constructs a panel data regression model to examine the association between cooperate governance and efficiency performance for Taiwan and China, respectively. The empirical results are summarized as follow. First, the efficiency frontier of Taiwan and China are indeed different, and the cross frontier analysis reveals that the efficiency performance of Mainland China is better than that of Taiwan. The TI of Taiwan developed earlier than China and the early core competence development of Chians’s TI was transferred from Taiwan. However, due to the huge domestic demand and government’s strong support of China’s TI, today not only the size but also the value-added of TI, China is much larger than Taiwan. Second, the domestic institutional investor’s and the state-owned shareholdings are significantly correlated with the performance of companies in China. The management, foreign institutional investor’s shareholdings and the percentage of independent directors do not associate with the performance of China’s TI. Finally, the cooprate government variable are not associate with the performance of Taiwan’s TI.
8

黃金商品對投資績效的影響-信心指數及多空市場分析 / 黃金商品對投資績效的影響-信心指數及多空市場分析

洪榮吉 Unknown Date (has links)
本研究主係探討以投資者持有本國股票作為基礎投資組合,利用台灣五十成份股投資組合及金融期貨指數之月報酬率資料形成效率前緣,然後將本研究所選取之黃金產業GOX指數或以黃金現貨價格兩種黃金商品投資組合分別加入基礎投資組合中,觀察每個投資組合標的加入前後之投資機會集合之變化,是否基礎投資組合之效率前緣進一步向左偏移,並比較其優劣。此外進一步探討在兩種黃金投資組合加入基礎投資組合,分別在股市多頭及空頭市場時會不會產生相同的效果;並且藉由中央大學台灣經濟發展研究中心所調查訂定的消費者信心指數,以中位數區分為信心指數高或信心指數低兩組情境,並將兩種黃金商品投資組合在不同的情境依序分別加入基礎投資組合中,其基礎投資組合之效率前緣是否皆仍進一步向左偏移。實證結果發現,黃金現貨帶給基礎資產投資機會集合的貢獻,明顯優於黃金產業GOX指數,當檢定資產為黃金產業GOX指數時,「切點投資組合」差異W_1統計值上皆不具統計顯著性,整體而言當黃金產業GOX指數在加入投資組合之後,我們認為大部份的效果是來自分散原有的投資組合風險;然而黃金現貨在改善投資機會集合的貢獻上,來自「最小變異數投資組合」及「切點投資組合」的改善皆有顯著的效果。
9

不同投資策略在確定提撥制下之衡量及分析

謝竣宇 Unknown Date (has links)
確定提撥制是現今退休金制度潮流的趨勢,而在這個制度下,勞工最後所能累積的退休金總額及每月所能領到的月退休金額度和個人帳戶的投資結果有很大的關係,所以個人帳戶的投資績效成為勞工退休生活安全性最重要的因素。 本研究的目的在提供一個方法以評量投資績效,使得在每月提撥一定金額到個人帳戶的情形下,對於投資期間的經濟環境以隨機投資模型或情境分析模型加以考量後,可以在不同的投資策略及起始資產配置下,找到適合投資人的最佳投資策略及起始資產配置。在本研究中考慮了股票和長期債券兩種投資標的,而投資標的之投資報酬率變化則以隨機投資模型(Stochastic Investment Model)及情境分析(Scenario Analysis)兩種模擬方式為之,其中在隨機投資模型模擬的部分,不同的隨機投資模型對於經濟環境有不同的設定,也因此將得到不同的投資結果,本研究採用在英國學術上廣為研究的Wilkie投資模型(1986)及黃泓智等人於2005年證券市場發展季刊所推導之台灣投資模型,並利用蒙地卡羅模擬的方式來建構投資標的之報酬率。而在情境分析模擬的部分,則設定三種基本的投資報酬率趨勢,並假設三種投資報酬率趨勢服從均勻分配,而後考慮投資期間分成前後兩個時期,搭配而得九種情境。 本文將觀察不同的起始資產配置(股票資產配置之權重考慮由0%~100%,間隔為1%,共101組;債券資產的權重則為1-股票資產配置之權重,也就是100%~0%),並以投資組合保險中三種常見的投資策略:買入持有(Buy & Hold;BH)、固定比例混合法(Constant Mixture;CM)及時間不變性投資組合保護(Time-invariant Portfolio Protection;TIPP),作為投資策略。 在三種投資策略及每種投資策略有101個起始資產配置下,將可以得到303組不同的投資結果,而每一組投資結果中,都可找到個人帳戶於退休時的累積金額、在一定目標所得替代率下之破產機率,以及平均投資報酬率和投資報酬率之標準差,並將所得之投資組合報酬率之平均值為縱軸,標準差為橫軸作圖,找出效率前緣;也就是說,可以依個人帳戶持有人的風險,在其所能忍受的風險下,找到最適的起始資產配置及投資策略,及依這樣的起始資產配置和投資策略下所能得到的平均報酬。另外,更進一步以Sharpe ratio及Reward-to-VaR ratio、Reward-to-CTE ratio三個指標來衡量投資表現,找出在這三個指標下的最適起始資產配置和投資策略。 在前述中,都未考慮到交易成本對於投資結果的影響,但在現實的環境中,交易成本對於投資結果是有影響的,所以本研究也會在考慮交易成本下,找到情境分析和隨機模型下的投資結果及效率前緣,並找出三個投資指標的值來衡量投資表現。 / The defined contribution plan is the trend of retirement pension funds management, but under this plan, the total account values accumulated and the retirement benefits paid each month that labors can get are great related to the investment results of the individual accounts. That's why we said that the investment result of the individual accounts is the most important factor the labors care about. In this article, we will focus on the measure of investment results. We consider bond and stock as our holding assets, and set the investment rate of return in two methods, including scenario analysis and stochastic model. In the scenario analysis method, we set fourteen scenarios to reflect the changes of the investment returns of stocks. In the stochastic model method, we take use of Wilkie investment model to set the investment return rate of stocks and bonds and simulate enormous data to find the average investment rate of return. In each method, we will consider 101 different initial ratio of stock value and three different investment strategies: Buy & Hold(BH)、Constant Mixture(CM) and Time-invariant Portfolio Protection(TIPP). After setting the investment rate of return and investment strategies, we can find 303 different investment results under three investment strategies and 101 initial ratios of stock values. In each result, we can get the accumulated amounts, the income substitute rate and the average rate of return, and use the average rate of return as y-axis, standard deviation as x-axis to find the efficient frontier. That is, we can find the optimal investment strategies and initial ratio of stock value under the risk we can tolerant. We will also use Sharpe Ratio、Reward-to-VaR ratio and Reward-to-CTE ratio to measure the investment results, and find the optimal investment strategies and initial ratio of stock value basic on the three ratios. In practice, the transaction cost is an important factor that will affect the investment results, so we also find the investment results under different situations which had considered the transaction cost.
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台灣保險業另類投資工具風險控制與監理研究 / Risk Management and Regulation on Emerging Alternative Investments of Insurance Companies

游儷容, Yu, Li Jung Unknown Date (has links)
台灣壽險業的利差損問題持續存在,但若想要進一步開放新投資項目,應先檢視新投資工具之特性以及研究對應之保險監理規範之修訂。 本研究針對國外另類投資進行實證分析,考慮風險與報酬之間的抵換關係(Trade-Off),以Rockafeller and Uryasev (2000)以及Campbell,Huisman and Koedijk (2001)提出之投資組合模型,建立平均值-風險 值(Mean-Value-at-Risk)之 效 率 前 緣 和 平 均 值-條 件 風 險 值(MeanConditional Value-at-Risk)之效率前緣,探討另類投資對投資組合效率的影響,並檢視相關保險監理規範的適宜性。 實證結果顯示不同資產類別(Assets Class)之間的相關性低,加入另類投資的標的能夠提升投資組合的效率,因此建議可以開放一些另類投資的項目,或是設定門檻進行監理。 / Recently, many insurance companies in Taiwan increased their investments in foreign countries substantially due to the inadequacy of domestic investment markets. Some insurers started or have been preparing to invest in emerging alternative investment tools such as private equity funds and hedge funds. However,there is a trade-off between return and risk. In this study we utilized the methods developed by Rockafeller and Uryasev (2000) and Campbell, Huisman, and Koedijk (2001) to conduct risk-return analyses for the insurance companies who are interested in alternative investments. Our approach extends the traditional Mean-Variance approach by introducing value at risk (VaR) and conditional VaR as risk measures. We found that the correlations among asset classes were low and alternative investments could enhance the investment efficiency of insurance companies. We suggest loosening some regulations accordingly.

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