近年來有很多關於退休金計畫的研究主要在探討從確定給付計畫(defined benefit plan)轉向確定提撥計畫(defined contribution plan)趨勢的影響。而這些早期的研究(Clark and McDermed(1990 and 1993), Gustman and Steinmeier(1992), Ippolito(1985, 1986, 1993, and 1997), and Kruse (1995); Papke(1994, 1996)and Papke, Petersen and Poterba(1996)主要是利用計畫個數的改變或者是計畫參與者人數的增減來作為衡量此一趨勢影響力的指標。然而，這兩項指標從退休收入多寡的觀點來看，卻無法反應此一趨勢對於員工福利的影響程度。Wang andVanDerhei(2000)利用了「雇主退休金成本」的新概念，探討此一趨勢的影響。而本篇論文將要延續Wang and VanDerhei(2000)的研究，藉由衡量雇主慷慨程度的改變，進一步分析此一趨勢對於員工未來退休收入的影響程度。為了檢視雇主退休金慷慨度是否有隨著時間以及環境變化而有所不同，我們利用OLS迴歸模型來分析在兩段期問中（1985年與1996年）雇主退休金慷慨度的變化。結果發現在確定給付計畫及401(k)計畫之下，退休金計畫存在的時間愈長以及工會的支持對於雇主慷慨程度都有正面的影響。在財務變數方面，我們則是發現不論哪一種型態的退休金計畫，稅前收入金額的多寡對於雇主慷慨程度均具有正面的影響。此外，利用Chow Test，我們發現確定給付計畫在1985年和1996年的確具有結構上的改變，進一步分析之後，發現退休金計畫存在時間愈長、工會的支持、金融相關產業、固定資產佔總資產的比例以及稅前收入金額的多寡對於1996年確定給付計畫下之雇主退休金慷凱度的正向影響遠大其對於1985年的確定給付計畫。在員工退休福利上，我們則是發現401(k)計畫的雇主相對提撥率在過去20年有明顯地成長，這意味著401(k)計畫下的員工在過去20年裡的退休福利有明顯的增加。 關鍵字：退休金趨勢、雇主退休金慷慨度、確定給付計畫、確定提撥計畫、401(k)計畫 / Much debate has devoted in recent pension literature to discuss the impacts of current pension trend toward defined contribution(DC) plans, especially the substitution effect between 401(k) and other pension plans. However, the“generosity”of the employer pension plan deserves little attention. This paper analyzes the impacts of the effects of this trend on workers' future retirement income by measuring the changes of employers' pension generosity. We construct a panel data of firms that sponsor at least one pension plan in 1985 and compare the changes of their pension generosity for DB, DC and 401(k) plans between 1985 and 1996. OLS Regression Models are adopted to analyze the generosity of employers' primary plan and supplemental plan and Chow test is conducted to test the structural changes between 1985 and 1996. Our results find that plan age and union status have positive impacts on employers' generosity ofDB and 401(k) plans. For financial variables, pretax income is an important consideration to employers' generosity disregarding the type of plan. In addition, we find that there was a structure change ofDB plans between 1985 and 1996 and that union status,plan age, financial etc. industry, proportion of fixed assets and pretax income have greater positive impacts on employers' generosity ofDB plans in 1996 than in 1985. For employees' retirement income, the matching rates have grown over the last two decades and this stands for that employees covered by 401(k) plans have received better retirement benefit over the last two decades. Key words: Pension trends; Employers' generosity; Defined benefit plan; Defined contribution plan; 401(k) plan

本研究探討長期投資人之最適資產配置問題，並著重於通貨膨脹風險之分析。第一部份討論確定提撥退休金制度下，機構投資人或高所得自然人如何擬定投資策略規避通貨膨脹風險，達到極大化期末財富效用期望值。此研究擴展Battocchio與Menoncin (2004)所建構資產模型，不僅探討市場風險，亦考量通貨膨脹不確定性與基金費用誘因、下方風險保護兩機制，研究對資產配置行為之影響，並依動態規劃方法求得投資策略公式解。第二部份則強調下方風險之重要性，檢視在最低保證收益下，長期投資人跨期資產配置之財富管理議題，並回顧Deelstra et al.(2003)之模型架構，依平賭方法求得投資策略公式解，研究結果顯示基金投資策略可表示為最適CRRA(γ,T)型態共同基金與最低收益避險之組合。另一方面，如何估計通貨膨脹風險亦為本文強調之重點。Campbell和Viceira (2001)首次納入通貨膨脹風險並探討跨期投資議題，結論市場缺乏通貨膨脹連動投資標的時，投資人將減碼長期債持有比例。Brennan和Xia (2002)假設通貨膨脹率服從Ornstein-Uhlenbeck過程，結論投資人之避險需求隨持有債券到期日與投資期限改變。但以上結論未將通貨膨脹學習機制納入模型，因此，在第三部份提出依學習機制修正之投資策略可顯著增加財富效用，並分析在不同參數設定下，學習機制對於期末財富效用之影響。 / In this study, we study three essays of asset allocation problem for long term investors, which means that in this discourse we emphasis the importance of inflation risk. In the first topic, we derive the dynamic optimal investment strategy of the defined contribution pension schemes which include two mechanisms of partial floor protection and incentive fees and their benchmarks. We find investors should hold high proportion of stock index fund to hedge the inflation risk; moreover, the ratio of incentive fees to the setting of benchmark will change the optimal investment trend of underlying assets. In the second topic, we introduce the optimal investment portfolio with minimum guarantees and show that the fund manager should adjust the optimal weights of underlying assets with the ratio of the guarantee fund's value to the value of fund. Finally, this work focuses on how to precisely predict the dynamics of inflation rate. We apply learning method to adjust the prediction of inflation process and we use numerical analysis to study the effect of learning mechanism under different parameter setting.

退休金是退休人未來生活的依靠，確保在退休後能得到適足的退休給付，政府在退休金上實施保證收益制度，此制度為最低保證利率與投資報酬率連結。本文探討退休金給付標準為確定提撥制，當退休金的投資報酬率是根據其連結之股價指數的表現來計算時，股價指數報酬率的模型假設為馬可夫調控跳躍過程模型，考慮市場狀態與布朗運動項、跳躍項的跳躍頻率相關，即為Elliot et al. (2007) 的模型特例。使用1999年至2012年的道瓊工業指數與S&P 500指數的股價指數對數報酬率作為研究資料，採用EM演算法估計參數及SEM演算法估計參數共變異數矩陣。透過概似比檢定說明馬可夫調控跳躍過程模型比狀態轉換模型、跳躍風險下狀態轉換模型更適合描述股價指數報酬率變動情形，也驗證馬可夫調控跳躍過程模型具有描述報酬率不對稱、高狹峰及波動叢聚的特性。最後，假設最低保證利率為固定下，利用Esscher轉換法計算不同模型下型I保證之確定提撥制退休金的評價公式，從公式中可看出受雇人提領的退休金價值可分為政府補助與個人帳戶擁有之退休金兩部分。以執行敏感度分析探討估計參數對於馬可夫調控跳躍過程模型評價公式的影響，而型II保證之確定提撥制退休金的價值則以蒙地卡羅法模擬並探討其敏感度分析結果。 / Pension plan make people a guarantee life in their retirement. In order to ensure the appropriate amount of pension plan, government guarantees associated with pension plan which ties minimum rate of return guarantees and underlying asset rate of return. In this paper, we discussed the pension plan with defined contribution (DC). When the return of asset is based on the stock indices, the return model was set on the assumption that markov-modulated jump diffusion model (MMJDM) could the Brownian motion term and jump rate be both related to market states. This model is the specific case of Elliot et al. (2007) offering. The sample observations is Dow-Jones industrial average and S&P 500 index from 1999 to 2012 by logarithm return of the stock indices. We estimated the parameters by the Expectation-Maximization (EM) algorithm and calculated the covariance matrix of the estimates by supplemented EM (SEM) algorithm. Through the likelihood ratio test (LRT), the data fitted the MMJDM better than other models. The empirical evidence indicated that the MMJDM could describe the asset return for asymmetric, leptokurtic, volatility clustering particularly. Finally, we derived different model's valuation formula for DC pension plan with type-I guarantee by Esscher transformation under rate of return guarantees is constant. From the formula, the value of the pension plan could divide into two segment: government supplement and employees deposit made pension to their personal bank account. And then, we done sensitivity analysis through the MMJDM valuation formula. We used Monte Carlo simulations to evaluate the valuation of DC pension plan with type-II guarantee and discussed it from sensitivity analysis.

員工持股計畫是由財經律師Louis Kelso所創，在美國已行之多年，廣為美國企業所採。最早的員工持股計畫是一種為了和平地從資本家手中移轉資本給員工、縮減貧富差距的工具。為了使這個計畫可以持續有效地運作下去，立法者將員工持股計畫為退休金計畫的一種，使員工必須長期持有股票，直到退休。然而在實務運作上，員工持股信託經常被運用為防止敵意併購的工具。尤有甚者，某些公司內部人會利用員工持股計畫為自己取得大量資金、移轉投資風險,但仍可保留對於公司的控制力。這些行為都有可能對股東及員工造成不利的影響，但在現行法制下，只能仰賴司法者透過判決保護這些經濟及資訊上的弱勢族群。 在台灣，員工持股計畫雖然已廣為許多企業所採用，但是發展了將近20年，只能成為另一種員工持有股票的工具。員工擁有的股票數量並不足以使其在股東會上贏得一個受公司內部人重視的地位，也不足以倚賴這些股票作為退休金之用。這種規模上的差異是台美員工持股計畫最關鍵的不同點。小規模雖然使員工持股計畫帶來的優勢少了許多，但相對地也減低許多代理成本，至今未有員工持股計畫侵害大量員工利益的事件爆發。然而這不表示員工持股計畫在台灣就是個可以被忽略的問題，若能在未來建立一套有效率的立法制度，使員工持股計畫的規模擴大，員工將可因此享受到更多公司盈餘，並且使其退休生活受到保障。相對地，參考美國員工持股計畫的問題後，也可以預先設想未來可能發生的弊端，未雨綢繆。本文相信，一個有效率的員工持股計畫，可以實現解決貧富不均的理想。 / Employee stock ownership plan (ESOP) which is created by Louis Kelso is brought to practice for many years. Many enterprises use it as their retirement pension plan. The earliest employee stock ownership plan to transfer the capital frome capitalists to labors and reduce the disparity between the rich and the poor.In order to make the plan work out continueously and effectively, the legislator devise ESOP as a pension fund which makes employee own stock chronically until they retires. However, in practice, ESOP is usually exercised for preventing hostile takeover. Moreover, some company insiders may use ESOP TTO get a great deal of capital and transfer the investment risk, but still own the controlling power to their company. This behaviors will cause some harmful effects to the shareholders and the employees, but in the current legal system,the only one we can depend is the judge who can protect the minority in the economic and the information. ESOP is exercised by many enterprises in Taiwan. But after 20 years, it can only become one of the tools which assist employees to acquire company stocks.The number of shares which employees owns can’t make them have a posi-tion which let the company insiders take account in the shareholder committee and have enough amounts for their retirement pensions.This disparity in scale is the keypoint what is different between Tiwan and the U.S. ESOP. Althoygh small scale makes the adventage of ESOP decrease, it reduce lots of agency costs. To this day, there’re not any events which injure the interests of employees by ESOP. Never-theless, it doesn’t mean that ESOP in Taiwan is a issue which can be neglected. If we can establish an efficient legal system and extend the scale of ESOP, employees can obtain more company interests and have a security of their retirement life.In the opposite, after researching the problem of the U.S. ESOP, we can assume the culpably misconduct which will happen in the future and repair the house before it rains。Ｉ believe that a efficient ESOP can realize the ideal to solve the problem of uneven distribution of the wealth.