• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 166
  • 140
  • 26
  • Tagged with
  • 166
  • 166
  • 79
  • 62
  • 60
  • 57
  • 54
  • 52
  • 47
  • 45
  • 41
  • 41
  • 37
  • 33
  • 32
  • 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.
51

應用Nelson-Siegel系列模型預測死亡率-以英國為例

宮可倫 Unknown Date (has links)
無 / Existing literature has shown that force of mortality has amazing resemblance of interest rate. It is then tempting to extend existing model of interest rate model context to mortality modeling. We apply the model in Diebold and Li (2006) and other models that belong to family of yield rate model originally proposed by Nelson and Siegel (1987) to forecast (force of) mortality term structure. The fitting performance of extended Nelson-Siegel model is comparable to the benchmark Lee-Carter model. While forecasting performance is no better than Lee-Carter model in younger ages, it is at the same level in elder ages. The forecasting performance increases for 5-year ahead forecast is better than 1-year ahead comparing to Lee-Carter forecast. In the end, the forecast outperforms Lee-Carter model when age dimension is trimmed to age 20-100.
52

臺北市稅捐稽徵處各分處稽徵績效之研究—三階段資料包絡分析法之應用 / A study on performance of branches of Taipei revenue service - An application of three-stage data envelopment analysis

王必涵, Wang, Pi Han Unknown Date (has links)
稅捐分處是最接近民眾之第一線機關,直接影響民眾對稅捐機關之觀感,其亦為最小的單位,卻肩負稅收稽徵、防止逃漏、為民服務等業務,故衡量分處的稽徵績效刻不容緩。本研究以臺北市稅捐稽徵處所屬13個分處為研究對象,並以員額、稽徵成本與設備數量等作為投入項、以各稅實徵淨額、違章裁罰金額、欠稅清理金額與人民申請案件數作為產出項,運用三階段資料包絡分析法進行衡量,評估臺北市稅捐稽徵處所屬各分處之技術效率,探討外生因素對產出差額的影響,並與原稽徵績效考核成績進行比較。實證結果顯示,在排除外生因素之影響後,整體效率值是較前提升的,而造成無效率的原因,部分可歸責於資源的浪費、部分可歸咎於未達最適規模;外生變數對大部分的產出差額具顯著影響,轄區內營業家數愈多,稅收金額較高;位於臺北市南區,稅課收入亦較多;前年平均國民生產毛額對大部分技術效率有負向影響;實務面之稽徵績效考核因考慮面向較廣、涉及過多非相關考評項目而淡化了各分處稽徵效率,為使對分處考核制度更為嚴謹,建議使用一套客觀的效率準則來衡量稽徵效率並加以評估,較能反映分處實際之稽徵績效。
53

農產品價格目標區之經濟穩定性:理論研究與數值模擬分析

楊琇雲 Unknown Date (has links)
No description available.
54

長期資料之隨機效果模型分析-公司每股盈餘與財務比率之關聯性研究 / Random effect model in longitudinal data--the empirical study of the relationship among EPS & financial ratios

楊慧怡, Yang, Hui-Yi Unknown Date (has links)
長期性資料(longitudinal data),是指對同一個觀察個體(subject)或實驗單位(experiment unit),在不同時間點上重複觀察或測量一個或多個變數。雖然觀察個體之間互相獨立,但就同一個個體而言,不同時間的觀察或測量常常是有相關性的。且觀察的個體之間可能由於一些無法測量的環境因素造成個體之間有差異,因此在傳統橫斷面分析中,假設其有相同迴歸係數的邊際模型可能不合理。隨機效果模型可以解決長期資料分析的相關,並假設每個個體的迴歸係數不同;此模型不但可以說明橫斷面資料的cohort效果,也可直接解釋長期資料的age效果;更可以區分個體之間與個體之內的變異。 本研究以1995年至2000年台灣11個產業中的100家公司之每股盈餘與各財務比率,作為實證分析的資料;分別配適每股盈餘與時間、產業別、時間產業別交互作用及財務比率及排除每股盈餘有異常值後之邊際效果模型(一般迴歸分析)及隨機效果模型,並比較其參數估計之異同。實證結果顯示,一般迴歸分析與假設誤差不相關且等變異下的隨機效果模型參數估計相似,但後者能區分變異為個體之間(between-subjects)與個體之內(within-subject)的變異。而假設誤差不相關且不等變異與假設誤差服從AR(1)且不等變異下的隨機效果模型估計相近。實證結果並顯示,在排除異常值後的模型參數估計,一般迴歸分析不論是估計值及顯著性大多沒有很大差別;而隨機效果模型的估計在排除異常值前後較有差別。特別是現金流量比率(CFR)原本為不顯著變數,在排除異常值後的模型配適全部變顯著性變數。 / The defining characteristic of a longitudinal study is that individuals are measured repeatedly through time. Although it is independent between subjects, the set of observations on one subject tends to be inter-correlated. Because there is some natural heterogeneity due to unmeasured factors between subjects, it is not corrected to assume they have the same regression coefficients. A random effect model is a reasonable description about the different regression coefficients, and it can resolve the inter-correlation of the observations on one subject. The major advantages of the random effect model are its capacity to separate what in the context of population studies are called cohort and age effects, and it can distinguish the variations between subjects and within subjects. This study describes the marginal model and random effect model, and shows their difference by real data analysis. We apply these models to the earnings per share (EPS) and other financial ratios of one hundred companies in Taiwan, which are distributed in eleven industries. The results show that the parameter estimates of the marginal model and random effect model are similar when error structure is independent and of equal variance. Furthermore, the latter can distinguish the variations between subjects and within subjects. However, the residual analysis reveals that the error structure may not be constant. Therefore, we consider heteroscedasticity error in random effect model. We also assume that error follows an autoregressive process (e.g. AR(1) model), which leads to the optimum among our results in terms of residual analysis. There are some observations that appear to be outlying from the majority of data. The results show little difference in the marginal models no matter whether those outliers are included. However, we obtain different results in the random effect models. Especially, the variable of “cash flow ratio” becomes significant once those potential outliers have been excluded, while it is not significant when all cases are fitted in the model.
55

不同評估績效期間之退休基金最適策略 / Optimal Strategy of Pension Fund Management Incorporating Distinct Projected Time Horizons

田嘉蓉, Tien, Chia-Jung Unknown Date (has links)
不同評估績效的長短顯著地影響基金的經營策略,相較於強調穩健經營的退休基金而言,此因素是否亦影響退休基金的運作,本研究嘗試應用隨機控制理論,將投資績效的時間因素納入決策考量,以隨機微分方程式描述退休基金資產和應計負債的動態隨機行為,以多期基金規劃的觀點,探討時間因素與最適策略之關連性。本研究應用Brennan、Schwartz與Lagnado(1997)的結果至負債導向的退休基金管理,建構多期資產負債管理模型,退休基金持有資產將分類為風險性的股票投資組合、長期債券和短期票券,並考量投資標的短期利率與長期利率之隨機性質,將基金提撥與資產配置視為可調節因子,給定風險評估測度,於不設定投資限制下計算各期最適投資比例及基金提撥;本研究並以私人退休金個案進行模擬分析,結果顯示此基金未來10年之最適提撥率介於4.2﹪與5.1﹪,就不同評估期限而言,5年評估期之提撥率於初期高於10年評估期,基金比率η=0.75之提撥率低於η=1;5年評估期之基金交易行為較10年期明顯劇烈,基金比率較低時,其交易變化程度較小,不同評估年限與基金比率將同時影響退休基金之最適提撥與投資策略。 / Distinct time horizons in measuring investment perfomance significantly influence the financial planning for the money managers. In this study, we explore this issue concerning the pension fund management that has focused on the asset and liability management to meet its future obligations. A stochastic control model is formulated in a continuous-time framework to obtain the closed form solution for optimal strategy. The time variation in expected returns introduced in Brennan, Schwartz and Lagnado(1997)is adopted in obtaining the optimal strategy using plausible future plan’s normal costs and accrued liabilities under distinct time horizons. Based on the proposed performance measurement, the optimal funding schedule and portfolio selections are determined dynamically without trading restrictions. A private pension scheme is selected and analyzed for numerical illustration. It shows that the optimal contribution rates are between 4.2﹪and 5.1﹪for this specific case. Comparing the funding schedules for distinct time horizons, we find that the contribution rates under 5-year period are higher than those under 10-year period in the beginning. The contribution rates given funding ratio at 75﹪are lower than those given at 100﹪. While the optimal trading behaviors of the pension fund managers for 5-year period are significant volatile than those for 10-year period. Their optimal trading behaviors have exhibited a reduced volatility under the lower funding ratios. The case study indicates that the distinct time horizon and the funding ratio play crucial roles in decision-making process for pension fund management.
56

隨機利率模型下台灣公債市場殖利率曲線之估計 / Yield Curve Estimation Under Stochastic Interest Rate Modles :Taiwan Government Bond Market Empirical Study

羅家俊, Lo, Chia-Chun Unknown Date (has links)
隨著金融市場的開放,越來越多的金融商品被開發出來以迎合市場參予者的需求,利率衍生性金融商品是一種以利率為標的的一種新金融商品,而這種新金融商品的交易量也是相當的可觀。我們在設計金融商品的第一步就是要去定價,在現實社會中利率是隨機波動的而不是像在B-S的選擇權公式中是固定的。隨機利率模型的用途就是在描述利率隨機波動的行為,進而對利率衍生性金融商品定價。本文嘗試以隨機利率模型估計台灣公債市場的殖利率曲線,而殖利率曲線的建立對於固定收益證券及其衍生性金融商品的定價是很重要的。在台灣大部分的利率模型的研究都是利用模擬的方式做比較,這也許是因為資料取得上的問題,本文利用CKLS(1992)所提出的方式以GMM(Generalized Method of Moment)的估計方法,利用隨機利率模型估計出台灣公債市場的殖利率曲線。本文中將三種隨機利率模型做比較他們分別為: Vasicek model (Vasicek 1977),、隨機均數的Vasicek 模型 (BDFS 1998) ,以及隨機均數與隨機波動度的Vasicek 模型 (Chen,Lin 1996). 後面兩個模型是首次出現在台灣的研究文獻中。在本文的附錄中將提出如何利用偏微分方程式(PDE)的方法求解出這三個模型的零息債券價格的封閉解(Closed-Form Solution)。文中利用台灣商業本票的價格當作零息債券價格的近似值,再以RMSE (Root mean squared Price Prediction Error)作為利率模型配適公債市場價格能力的指標。本文的主要貢獻在於嘗試以隨機利率模型估計出台灣公債市場的殖利率曲線,以及介紹了兩種首次在台灣研究文獻出現的利率模型,並且詳細推導其債券價格的封閉解,這對於想要建構一個新的隨機利率模型的研究人員而言,這是一個相當好的一個練習。 / With the growth in the area of financial engineering, more and more financial products are designed to meet demands of the market participants. Interest rate derivatives are those instruments whose values depend on interest rate changes. These derivatives form a huge market worth several trillions of dollars. The first step to design or develop a new financial product is pricing. In the real world interest rate is not a constant as in the B-S option instead it changes over time. Stochastic interest rate models are used for capturing the volatile behavior of interest rate and valuing interest rate derivatives. Appropriate models are necessary to value these instruments. Here we want to use stochastic interest rate models to construct the yield curve of Taiwan Government Bond (TGB) market. It is important to construct yield curve for pricing some financial instruments such as interest rate derivatives and fixed income securities.  In Taiwan Although most of the research surrounding interest rate models is intended towards studying their usefulness in valuing and hedging complex interest rate derivatives by simulation. But just a few papers focus on empirical study. Maybe this is due to the problems for data collection. In this paper we want to use stochastic interest models to construct the yield curve of Taiwan’s Government Bond market. The estimation method that we use in this paper is GMM (Generalized Method of Moment) followed CKLS (1992). I introduce three different interest rate model, Vasicek model (Vasicek 1977), Vasicek with stochastic mean model (BDFS 1998) and Vasicek with stochastic mean and stochastic volatility model (Chen,Lin 1996). The last two models first appear in Taiwan’s research. In the Chapter 3, I will introduce these models in detail and in the appendix of my thesis I will show how to use PDE approach to derive each model’s zero coupon bond price close-form solution. In this paper we regard Taiwan CP (cmmercial Paper) rates as a proxy of short rate to estimate the parameters of each model. Finally we use these models to construct the yield curve of Taiwan Government Bonds market and to tell which model has the best fitting bond prices performance. Our metric of performance for these models is RMSE (Root mean squared Price Prediction Error). The main contribution of this study is to construct the yield curve of TGB market and it is useful to price derivatives and fixed income securities and I introduce two stochastic interest rates models, which first appear in Taiwan’s research. I also show how to solve the PDE for a bond price and it is a useful practice for someone who wants to construct his/her own model.
57

隨機利率下外幣選擇權訂價理論與模擬 / Pricing Foreign Currency Options Under Stochastic Interest Rates

張雅琪, Chang, Yaa-Chi Unknown Date (has links)
政府為推動台灣成為亞太金融中心,逐漸放寬許多金融管制,因此,規避匯率風險將是台灣落實金融自由化與國際化的重要課題。 過去探討外幣選擇權訂價模式的文獻通常在利率固定的假設下進行研究,本研究將HJM利率模型應用於評價外幣選擇權,考慮國內外利率皆為隨機性,歐式與美式外幣選擇權的訂價。本文運用風險中立評價法,推導出與Grabbe(1983)類似的歐式外幣選擇權封閉解,並採用Amin and Bodurtha(1995)的模型設定,以間斷時間的HJM模型為基礎,運用模擬的方法決定美式外幣買權的價格,進而改變各參數的設定,進行敏感度分析。模擬結果顯示長天期的美式外幣買權對遠期利率波動度的敏感度較短天期大。本文呈現另一種外幣選擇權的評價模式,後續的研究可考慮將本文所採用的方法應用於外匯期貨選擇權、交換選擇權等衍生性金融商品的評價上。 第一章 緒論 第一節 研究背景與動機 1 第二節 研究目的 2 第三節 研究架構 3 第二章 相關文獻探討 第一節 歐式外幣選擇權之固定利率模式 4 第二節 歐式外幣選擇權之隨機利率模式 8 第三節 美式外幣選擇權評價模式 13 第三章 外幣選擇權定價模式 第一節 隨機利率下歐式外幣選擇權訂價理論 16 第二節 隨機利率下美式外幣選擇權訂價模式 26 第四章 模擬結果分析 33 第五章 結論與建議 43 附錄一 45 附錄二 46 附錄三 47 附錄四 49 附錄五、美式外幣選擇權電腦模擬程式 50 參考文獻 53
58

隨機波動度下選擇權評價理論的應用---以台灣認購權證為例 / Application of Option Pricing Theory Under Stochastic Volatility---The Case of Taiwan's Warrants

曹金泉, Tsao, Jim-Chain Unknown Date (has links)
摘要 本文是利用1998年底以前券商發行的15支認購權證為研究標的,試圖說明不同波動度的估計方法,會使得認購權證的理論價與市價產生不同的誤差,藉以提供券商在評價認購權證上作一參考。本文的實證結果發現:(1)在波動度的參數估計上,各模型均有波動度群集效果,但是訊息不對稱的效果各模型卻無一致性的結果;(2)在各模型的預測能力比較上,ARCH-M(1,1)模型都比ARCH(1,1)的預測能力佳。歷史波動度對於標的股的波動度小具有較佳的預測能力,而EGARCH-M(1,1)模型與GJR-GARCH-M(1,1)模型在預測波動度較大的標的股時具有較佳的預測結果;(3)以預測誤差百分比來比較各模型在預測認購權證上何者具有較小的誤差,結果發現:不論有無考慮交易成本及間斷性避險,預測能力最差的是歷史波動度,而預測能力最佳的則是隱含波動度模型,此乃因為台灣認購權證市場只有認購權證而無認售權證所致;(4)以市場溢價來比較那一支認購權證較值得投資者購買,結果發現:若權證處於價外,會使得市場溢價過高,而不利投資者購買;相反,若權證價格處於價內,則使得市場溢價較低,投資者購買較有利;(5)利用Delta法及Delta-Gamma法來計算大華01可發現:不同波動度的估計方法會影響該權證的涉險值,由於隱含波動度明顯高於其他方法所估算的值,故以隱含波動度計算的涉險值也就高於其他模型之涉險值。 目錄 謝辭 摘要 第一章 緒論 第一節 研究背景與動機 ………………………………………….1-1 第二節 研究問題與目的 ………………………………………….1-4 第三節 論文架構與流程 ………………………………………….1-5 第二章 文獻回顧 第一節 隨機波動度模型 ……………………………………….2-1 壹 Hull & White(1987)模型 …………………………..2-1 貳 Wiggins(1987)模型 ………………………………..2-3 參 Johnson & Shanno(1987)模型 …………………….2-4 肆 Scott(1987)模型 …………………………………...2-5 伍 Stein & Stein(1991)模型 …………………………..2-6 陸 Heston(1993)模型 …………………………………2-8 第二節 GARCH體系---波動度估計之方法 ……………………2-10 壹 GARCH模型 …………………………………………2-10 貳 EGARCH模型 ………………………………………..2-10 參 GJR-GARCH模型 ……………………………………2-11 肆 N-GARCH模型 ………………………………………2-12 伍 T-GARCH模型 ………………………………………2-12 第三章 研究方法 第一節 波動度之估計方法 ……………………………………….3-1 壹 歷史波動度 ……………………………………………3-1 貳 GARCH(1,1)模型 ……………………………………..3-2 參 EGARCH(1,1)模型 …………………………………..3-3 肆 GJR-GARCH(1,1)模型 …………………………...3-5 伍 ARCH-M(1,1)模型 ………………………………..3-7 陸 隱含波動度模型(Implied Volatility) ………………3-8 第二節 選擇權評價公式之探討 ………………………………….3-24 壹 Black & Scholes的選擇權評價模型 ………………...3-24 貳 考慮交易成本極間斷性避險下的選擇權評價模型 ...3-25 第四章 實證結果與分析 第一節 波動度的估計與預測能力 ………………………………4-1 第二節 選擇權評價理論的實證結果 …………………………4-18 第三節 認購權證涉險值(VAR)之衡量與應用 ………………4-53 第五章 結論與建議 ……………………………………………….5-1 附錄 …………………………………………………………附-1 參考文獻 …………………………………………………………Ⅰ
59

動態短期利率期限結構模型:臺灣票券市場之實證研究 / Dynamic short-term structure model-A empirical study on Taiwanese Note Market

方世明, Fang, Shi-Ming Unknown Date (has links)
本篇研究主要目的在於檢驗一般化一因子及二因子利率隨機過程模型何者對於臺灣貨幣市場利率 變動行為模式最具解釋能力。再運用模型所求得之 利率變動估計值及當期市場遠期利率,求解二項分 配未來短期利率之各結點估計值,形成二項分配利 率期限結構。由於二項分配利率期限結構為一任意 形態之樹狀結構,且同時考量過去利率波動程度及 市場對於未來之預期,故此一模型將可運用於對未 來利率水準之預測或作為存續期間模型之折現率以 改善利率風險衡量之理論限制。 本研究運用GARCH模型作為估計參數之計量模型。經由實證結果分析,可規納以下幾點結論: 一、一般化一因子模型較考量波動性之二因子模型對於臺灣貨幣市場利率變動行為模式更具解釋能力。二、利率隨機過程模型對真實市場利率變動之解釋能力,隨資料來源天期增加逐步降低。(30天期優於180天期)三、欲以利率隨機過程模型估計利率波動動變異數參數,應避免建構太長天期之二項分配利率期限結構樹狀估計值。四、二項分配利率期限結構模型上之結點估計值,可視為符合過去波動程度及市場預期之未來利率水準上下限可能值,作為投資決策準則。 五、二項分配利率期限模型結點估計值,不僅決定於變動率,同時受模型估計期數個數影響。當個數越多時,上下限偏離程度越大。
60

臺灣股票報酬率分配之實證研究 / An Empirical Study - The Distribution of Taiwan's Stock Returns

謝育萍, Hsieh Yu-Ping Unknown Date (has links)
本文主要目的在檢定臺灣股票報酬率是否為序列隨機;臺灣股票報酬率分 配是否符合常態分配、穩定分配。其中實證結果發現:拒絕臺灣股票報酬 率為序列隨機;拒絕臺灣股票報酬率分配呈常態分配、穩定分配。由於拒 絕臺灣股票報酬率為序列隨機,故將原資料隨機化後再次進行常態、穩定 分配之檢定、結果發現拒絕隨機化後之臺灣股票報酬率分配呈常態分配, 但不能拒絕隨機化後之臺灣股票報酬率分配呈穩定分配。

Page generated in 0.0229 seconds