本研究針對退休基金管理的兩項重要議題：提撥政策與資產配置作最適規劃之探討。由於傳統退休基金的評價僅考慮單一期間的離散時間模型，不若多期規劃的效率性，因此，本研究考量連續時間下，利用控制理論觀點，將提撥金額與資產配置視為可調節的因子，以風險最小化為最適定義，提供基金多期管理的有效方法。 首先，為充分反映退休基金管理時所面臨的不確定因素，本研究假設資產價值服從幾何布朗運動，並且經由隨機微分方程式描述退休基金所累積資產與應計負債的動態隨機性質。其次，考量基金管理所面臨的提撥風險與清償風險，給定能夠量化這些風險的評估測度，藉以監督退休基金於管理期間的經營績效，並且利用Bellman方程式求出最適的基金提撥與資產配置策略。 最後以勞動基準法規範下的企業退休金計劃為實證對象，透過動態模擬估計模型中之參數，並且利用數值方法求出所需的函數值，將控制理論與情境模擬連結，藉以檢視現行固定給付退休基金之最適策略。由實證結果可知，透過本研究的方法的確可以有效管理基金同時符合財務清償能力的要求。利用動態規劃所得的最適策略與給定的風險評估函數相關，因此，基金決策者可以依據基金的特性給定適當的風險評估函數，依照不同的投資期限擬定合適的基金策略。 / This study explores two critical issues in pension fund management: funding policy and asset allocation. The traditional valuation of pension fund is restricted in one-period setting under discrete-time framework, and it is not efficient comparing to the continuous-time models. Therefore, in this study, control theory is employed to obtain the optimal strategy based on a specific plan dynamics. Employer's contributions and investment proportions are treated as the controllers in our model. Optimal solutions are obtained by minimizing the given risk performance in monitoring the multi-period fund management. First, the stochastic differential equations are constructed to describe the dynamics of the funding levels and the accrued liabilities. Geometric Brownian motions are used to model the assets held by the fund manager. Secondly, a stochastic control model with given risk measurement is formulated in a continuous-time framework to investigate the optimal decisions. In our approach, the plan's normal costs and accrued liabilities are simulated through plausible scenarios while the optimal contribution and asset allocation are solved through Bellman equation. At last, a specific pension scheme under the regulation of the Taiwan labor standards law is studied for numerical illustrations. A monitoring mechanism linking plausible scenarios and the closed-form solutions are employed to scrutinize the funding policy and asset allocation. The optimal strategies are estimated through dynamic programming under realistic workforce scenario. According to the result, it shows that the methodology in this study can assist the fund manager in obtaining the plan's financial soundness. Meanwhile, the optimal strategy can fully incorporate the given risk measurement. Hence, the policy maker can input certain managerial considerations into the performance measure to investigate the stability and solvency issues.

No description available.

以前在台灣房地產開發市場上主要的房屋銷售模式是預售制度，這是受限於當時政治、經濟的環境條件下，所形成的特殊制度，主要的原因就是需要從市場中，獲得足夠的營運週轉資金；但是台灣的房地產市場在這幾年來逐漸轉變，已經出現為數不少的成屋銷售個案，主要著眼於當房地產市場景氣上揚時，延遲銷售能夠使專案獲得更大的報酬，而且當房地產專案融資的取得逐漸放寬，資金來源不在成為限制條件時，預售房屋可能已不再是唯一的銷售模式，且可能不再是最適銷售模式，但市場上房地產業者仍延續以前的思考模式，以融資比例的大小（有錢沒錢），作為判斷銷售時機的決策依據。本研究所想要研究的方向是最適銷售時機的選擇與融資決策是否會影響銷售時機的選擇，在各種不同市場條件下最適銷售時機與選擇權價值的變化。 本研究以實質選擇權（Real Options）模式探討新建房屋最適銷售時機，但以應用以前學者所推導的模式並不做模式的推導；首先以建立市場中專案營收的模式與建立實質選擇權決策模式，模擬房地產業者營運情境，並以隨機亂數帶入房價與融資利率模擬模式中，以模擬房地產市場中房價與融資利率，將模擬結果帶入所建立的模式中，模擬不同房地產市場條件下專案的營收，並藉由不同的決策值所模擬的專案營收，探討房地產市場中新建房屋的最適銷售時機的選擇與選擇權的價值。並且將模式中所應用的各變數予以獨立（在其他條件不變下，僅改變該變數）做敏感性分析，探討各模式中變數對於選擇最適銷售時機與實質選擇價值變化所產生的影響，以瞭解房地產市場中各外生變數，對於房地產市場新建房屋最適銷售時機與實質選擇權價值所可能造成的影響，與所應該注意的涵義。 第壹章 緒論 第壹節 研究動機與目的 1 第貳節 研究範圍與限制 5 第參節 研究架構 7 第貳章 產業分析與個案訪談 第壹節 銷售時機 11 第貳節 不動產金融 25 第參節 文獻探討與個案研究對本研究的涵意 28 第參章 文獻探討 第壹節 最適銷售時機模式 32 第貳節 文獻探討與個案研究對本研究的涵意 51 第肆章 模式建構與模式設計 第壹節 最適銷售時機 56 第貳節 研究設計 67 第伍章 實證結果分析 第壹節 融資決策與最適銷售時機 75 第貳節 實質選擇權價值敏感性分析 81 第參節 最適銷售時機選擇敏感性分析 90 第陸章 結論與建議 第壹節 研究結果涵義 104 第貳節 建議 110 參考文獻 中文部份 114 英文部份 115

行列設計中存在有空點的情形時，欲做全域最適行列設計的配置將會變得複雜許多，所以在本文中我們證實出將全域最適行列設計做橫向或縱向複製後，所得之設計不論其試驗處理在行或列出現之次數為"平衡"或"不平衡"，均依舊為全域最適行列設計。此外，將若干個試驗處理個數相同之全域最適行列設計做橫向或縱向地合併，所形成的新設計亦為全域最適行列設計，因此許多不同空點型式的行列設計之最適性便可證實。最後，根據實例說明若一行列設計橫向複製為全域最適行列設計，但縱向複製則不為時，在何種情況下，採直接縱向複製所得之行列設計，仍能相近於全域最適行列設計。

公共支出與公共收入乃為一體兩面之事。A.C. Pigou於1947年就曾提出租稅融通方式不同，將影響公共支出水準的看法，他並且認為當政府採用扭曲性租稅來融通公共財時，會產生超額負擔使得公共財提供的邊際成本增加。基於這項觀點，就不宜再以公共財的直接成本作為最適公共支出水準的依據，而應將扭曲性租稅本身可能造成的扭曲效果納入考慮。而這也表示了P.A. Samuelson於1954年提出的最適公共財提供條件ΣMRS=MRT應該被修正，且視融通公共財的租稅方式所產生的影響而應有不同的最適公共財提供條件。 　　本篇論文的目的，即在討論各種不同的租稅制度融通下，以最適公共財提供條件的修正，分析修正項目對最適公共支出水準的影響，並與過去的文獻作一比較，以期得出不同的租稅制度融通和最適公共支出之間的關係。

本研究探討長期信託基金（諸如退休基金，人壽保險公司等）之固定收益債券多期資產配置，利用時間可加性之效用函數描述投資者於投資期限時對財富大小之風險偏好程度，滿足基金之長期最適效益目標，為避免模型過於複雜，本文假設於動態完備市場中針對基金所持有之資產執行動態資產配置，建立財務動態調整機制以評量基金到期之獲利表現。為實際反應市場之風險程度，持有資產將利用隨機擴散過程表示，短期市場利率採用單因子Vasicek隨機模型表示，本文以給定金融市場之情境假設，說明不同到期日之債券為適當之獲利投資及避險工具，本研究之多期資產配置模型主要參考Cox與Huang (1989, 1991)與Sorensen (1999)，將未來財富過程利用平賭過程表示，給定不同投資限制條件、風險偏好程度與市場系統風險，以擬似動態規劃實際計算與比較每期之最適資產配置。 / This study attempts to investigate the hedging behavior through multi-period asset allocation strategy for the long-term fund manager, i.e., pension fund managers, life insurers, etc. Time additive utility function is employed to depict the risk preference of the investors during his investment time horizon. Based on their long-duration liabilities, assets held by the fund manager are employed in hedging and speculating under dynamic complete market assumption. To fully reflect the financial risks from the market, a risk management mechanism is implemented to monitor the long-term financial soundness. Short-term interest rate model proposed by Vasicek is employed to characterize the diffusion pattern of the invested assets. Current financial market information are incorporated and investigated to portray the hedging strategy through fixed income securities with various maturities. The quasi-dynamic approach proposed in Cox and Huang (1989, 1991) and Sorensen (1999) are implemented to construct the optimal asset allocation model. The optimal strategy is examined through maximizing the indirect utility function through the optimal growth portfolio. Finally, the hedging behaviors are compared and fully explored under various market scenarios.

本論文包含二篇與公司財務相關之文章，第一篇文章嘗試在考量總體經濟條件和公司生產力衝擊下，建構一個簡單結構式模型以探討公司之資本結構決策。特別的是，由該模型可得到公司最適負債比率與總體經濟條件衝擊之報酬波動性呈反向關係，惟公司最適負債比率與公司生產力衝擊之報酬波動性呈正向關係。第二篇文章係利用對稱寡占產業均衡模型，以探討產業內經理人薪酬決策之異質性。即使產業內所有公司皆為同質，在模型均衡下存在有些公司會採取激勵性薪酬，而其他公司則不採取激勵性薪酬。該模型預期當市場競爭性增加時，產業內公司經理人薪酬決策會更具異質性。此外，上述二篇文章皆分別以美國製造業資料進行實證，並且實證結果均符合其模型之預期。 / This dissertation proposes two essays about corporate finance. Essay one develops a simple structural model to investigate a firm’s capital structure choices in consideration of macroeconomic conditions and firm-level productivity shocks. The model particularly generates the implication that the optimal debt ratio is negatively correlated to the return volatility of macroeconomic conditions, but positively correlated to that of firm-level productivity. Essay two is contributed to explore the heterogeneity of the compensation decision within the industry by employing a symmetric oligopoly industry equilibrium model. Within the equilibrium some firms will adopt incentive pay while others will not, even though all firms are ex ante identical. The model predicts that there is more heterogeneity in the compensation decision as the intensity of market competition increases. Both of the two essays further provide empirical evidence of the US manufacturing industry to support the model implications.

已開發國家中，無論個人或是法人所擁有之財富大多透過金融中介機構管理，因此，財富委由他人管理衍生出現代資本市場中重要的委託關係。委託人與基金管理人產生委任契約時，也必然產生代理問題，即雙方利益不一致所額外增加的成本。為降低代理成本，於委任合約加入對管理人下檔投資風險的要求成為降低代理成本的重要機制。本研究因此探討當基金管理人面對契約存在最低報酬要求時，如何進行最適資產配置決策，並同時分析下檔風險限制改變時對管理人投資行為的影響。研究結果顯示，委任合約增加經理人最低保證收益時，基金管理人傾向增加持股，而經理人風險趨避程度增加時，將減少風險性股票資產，進而持有債券；如果投資目標收益於受委託期間皆不改變，將造成經理人持有債券組合以規避下檔風險，同時卻喪失追求資本利得。 / In most developed countries, financial wealth is not managed directly by the investors, but through a financial intermediary. Hence, the delegated portfolio management is one of the most important principal-agency relationships in the current economy. In addition to that, the principal-agency relationships between the investor and portfolio manager must produce agency cost. In order to reduce these costs, the mandates in the contract become an important factor in reducing the principal-agent problem in a delegated portfolio management framework. In this research, we study how fund managers do asset allocation when they face some guaranteed returns and the relationships between the choices of mandates and the behavior of fund managers. We suppose that the objective of the delegated fund managers is to maximize the expected utility of wealth of the long-term fund at the end of each period and fund managers also have to fulfill some constrains given at the beginning. Finally, we explain how fund managers do optimal asset allocation by our model and some numerical analysis.

2011年，美國政府在經歷次級房貸和高軍事支出的雙重壓力下，爆發高度財政赤字的問題，造成歐巴馬政府面臨調高債務比例與債務上限的壓力。然而，在眾多的輿論聲中，美國民主黨與共和黨在八月底達成下列協議，減少政府支出、提高債務比例以及增加債務上限等；但是，是否這些方式將改善美國經濟？本篇文章在動態隨機一般均衡(DSGE)架構下，建立一個封閉經濟體系，並將政府支出加入私人廠商部門，透過公共投資，幫助私人廠商增加產出；並且在政府僅採行公債和徵稅融通下，找出一個最適的債務持有比例，使國內福利為最高。而本文發現政府進入生產部門時，將影響最適債務持有比例。即是，隨著政府支出生產彈性越大，最適債務持有比例也會上升，而在基準參數下，我們將會得到最適債務持有比例為百分之十的結論。 / In 2011, under the pressure of subprime mortgage and high military expenditure, the U.S. government accumulated high fiscal deficit, and the Obama government faced the pressure of raising debt ratio and raising debt ceiling. However, among the huge debates, the Republican Party and Democratic Party reached the deal in August which included cut-down government expenditure, raise debt ratio, raise debt ceiling, and so on. But, will these ways improve the U.S. economy? This paper follows the dynamic stochastic general equilibrium (DSGE) framework to construct a closed economy, which the government helps private firm to production through public investment. Besides, given that government only undertakes debt financing and tax financing, we try to find an optimal debt ratio which makes the highest domestic welfare. In our finding, if the government enters private production sector, the optimal debt ratio will be influenced. That is, the optimal debt ratio will increase with the production elasticity of government expenditure. Under the benchmark parameter, the optimal debt ratio is 10 percent.

在生態學與生物學上，物種數常作為生物多樣性的指標，以估計單一群體物種數為例，較知名的方法首推Good (1953)以在樣本中出現一次的物種為基礎，提出的物種數估計方法堪稱的先驅，隨後許多文獻延伸Good的想法，發展出許多的估計方法，例如Burham and Overton (1978)的摺刀估計法，Chao and Lee (1992)則以涵蓋機率方式估計。相對而言，兩群體的共有物種數的研究少有人探討，目前以Chao et al. (2000)的估計式較為知名。 本研究參考Good (1953)提出估計未發現物種出現機率的想法，估計未發現共有物種的機率，並以Burham and Overton (1978)中應用摺刀法估計物種數的概念，建立一階摺刀估計式與變異數，且另行以多項分配公式推導變異數估計式，進行電腦模擬與實際資料驗證並與Chao et al. (2000)提出的共有物種估計式比較。最後根據Rasmussen and Starr (1979)以抽樣成本建立最適停止規則的概念，應用於本研究所提出的估計式，並經由電腦模擬找出抽樣成本與物種分佈均勻程度的關聯，可作為設定停止規則的依據。 / The number of species is often used to measure the biodiversity of a population in ecology and biology. Good (1953) proposed a famous estimate for the number of species based on the probability of unseen species. Subsequently, many studies applied Good’s idea to create new estimation methods, For example, the Jackknife estimate by Burham and Overton (1978), and the estimate by using the sample coverage probability in Chao and Lee (1992) are two famous examples. However, not many studies focus on estimating the number of shared species of two populations, except the method by Chao et al. (2000). In this study, we modify Good’s idea and extend the Jackknife method of Burham and Overton (1978) to develop the estimate for the number of shared species of two populations. In addition, we also establish the variance formula of the estimator by using the multinomial distribution. Subsequently, we use computer simulation and real data sets to evaluate the proposed method, and compare them with the estimator by Chao et al. (2000). Finally, we adapt the idea of optimal stopping rule by Rasmussen and Starr (1979) and combine it with the proposed jackknife estimate. We found that using the sampling cost as the stopping rule is a feasible approach for estimating the number of shared species.