本文於確定提撥退休金制度下，探討基金經理人如何決定最適資產策略規避薪資所得及通貨膨脹之不確定風險，求得期末財富效用期望值極大化。本研究首先擴展Battocchio與Menoncin (2004)所建構之資產模型，我們不僅探討來自市場之風險，同時考量薪資所得、通貨膨脹與費用率之不確定性，研究其對最適資產配置行為的影響，建構隨機控制模型，以動態規劃方法求解Hamiltonian方程式，研究結果顯示，我們可利用五項共同基金分離定理來描述投資人之最適投資決策：短期市場基金、狀態變數避險基金、薪資所得避險基金、通貨膨脹避險基金與現金部位。數值結果顯示，股票持有部位中通貨膨脹避險基金佔有最大的成份，債券持有部位中通貨膨脹避險基金與狀態變數避險基金佔有最大的成份。 關鍵字：確定提撥、薪資的不確定性、通貨膨脹、隨機控制、動態規劃 / In this study, we investigate the portfolio selection problem in order to hedge the labor income and inflation uncertainties for defined contribution (DC) pension schemes. First, we extend the previous work of Battocchio and Menoncin (2004) that allowed the state variables (i.e., the risks from the financial market) and a set of stochastic processes to describe the inflation, labor income and expense uncertainties. A five-fund separation theorem is derived to characterize the optimal investment strategy for DC pension plans to hedge the labor income and the inflation risks. Second, by solving the Hamiltonian equation in the three-asset framework, we show that the optimal portfolio consists of five components: the myopic market portfolio, the hedge portfolio for the state variables, the hedge portfolio for the inflation risk, the hedge portfolio for the labor income uncertainty and the riskless asset. Then we explicitly solve the optimal portfolio problem. Finally, the numerical results indicate that the inflation hedge portfolio comprises the overwhelming proportion of stock holdings in the optimal portfolios. In addition, the inflation hedge portfolio and the state variable hedge portfolio constitute the overwhelming proportions of bond holdings. Keywords: defined contribution; salary uncertainty; inflation; stochastic control; dynamic programming.

本文分成兩個部分探討失業者的工作搜尋決策，第一部分利用遞延選擇權模型模擬市場景氣、預期工作機會出現機率、不確定性等因素對失業者工作搜尋決策的影響。第二部份利用2006年至2010年主計處的「人力資源調查」及「人力運用調查」資料從事實證分析。本文從實證分析中驗證以下的模擬結果：一、市場上的工資波動率與失業者的保留工資有正向關係，與移轉到就業的機率有負向關係。二、失業者對工作機會出現機率的預期較高時，擁有較高的保留工資，移轉到就業的機率較低。另外，學習速度較快的失業者在搜尋工作的過程中會以較快的速度下降保留工資，移轉到就業的機率較高。三、失業者對於工作搜尋報酬的不確定程度較高時，擁有較低的保留工資，移轉到就業的機率較高。 / This thesis consists of two parts. The first part is devoted to applying a real option approach to simulate the impacts of market prospect, expected offer arrival rate, and uncertainty on job search decisions. The second part provides an empirical illustration to validate the simulation results by using unemployment data from the 2006-2010 Taiwan Manpower Utilization Survey. The main findings of this thesis can be summarized as follows: (i) The wage volatility is related positively with the reservation wage of the unemployed, but inversely with the transition probability into employment. (ii) If a rising offer arrival rate is expected, the unemployed increase reservation wages and thus decrease transition probabilities. Furthermore, higher learning speed acts to intensively lower the reservation wage. (iii) When the degree of payoff uncertainty is higher, the unemployed decrease reservation wages and thus increase transition probabilities.

本研究旨在探討我國生醫產業公開說明書之資訊揭露程度對初次公開發行 (IPO, initial public offering)定價效率及次級市場投資人信念異質性程度之影響。當初級市場認購人間資訊不對稱程度越大時，IPO價值之事前不確定性越高。為均衡各交易參與者之利益，發行人與承銷商將主動提升公開說明書之資訊揭露程度，以制定適當的IPO折價幅度、維持承銷商合理的承銷風險與報酬，並協助認購人適切評定IPO之價值。異質信念觀點強調次級市場投資人對企業價值看法之歧異程度越大，將導致IPO蜜月期報酬之異常現象。本研究預期若無形資產密集度越高，IPO事前不確定性越大，則IPO折價幅度越大，並預期公開說明書之資訊揭露程度將改變無形資產密集度對折價幅度之影響程度。此外，本研究預期，生醫產業IPO案件之無形資產密集度、公開說明書之資訊揭露程度及者配售情形均可能影響投資人信念異質性，進而影響掛牌初期之成交價量表現。 本研究參考國外證券主管機關之無形資產資訊揭露規範，自行建立資訊揭露指標，系統性地衡量我國生醫產業公開說明書之資訊揭露程度，並以多元迴歸分析檢測假說。實證結果顯示，我國生醫產業IPO案件之無形資產密集度對IPO折價幅度存在顯著正向影響；公開說明書之資訊揭露程度改變無形資產密集度對折價幅度之影響程度；發行人之無形資產密集度、公開說明書資訊揭露程度及初級市場配售情形皆影響掛牌初期之投資人信念異質性及價格震盪幅度。研究結果證實公開說明書之資訊揭露提供預期效益，及初級與次級市場間之資訊相互流通、交易行為相互連動之關聯性。 / This research examines how the disclosure level of prospectus influences the efficiency of IPO (initial public offering) pricing in the primary market and the degree of divergence of opinions in the secondary market. The literature of IPO underpricing suggests that ex ante uncertainty due to information asymmetry has a positive impact on IPO discount and voluntary disclosure of prospectuses may reduce the uncertainty level. This research hypothesizes that, for biotechnology companies, a greater disclosure level of prospectuses would lower the impact of intensity of intangibles on IPO discount. Further, this research hypothesizes a relation between the pricing efficiency in primary market and the level of divergence of opinions in secondary market. The empirical results from regression analyses of hand-collected data show that, for biotechnology IPOs, the disclosure level of prospectuses reduces the impact of the intensity of intangibles on IPO discount. In addition, the intensity of intangibles, disclosure level of prospectuses, and trading behaviors in the primary market have an effect on the degree of divergence of opinions in the secondary market. In sum, this research evidences the expected benefits of the increased level of voluntary disclosure of prospectuses for biotechnology IPOs.

本文包含關於估計風險與動態資產配置的兩篇研究。第一篇研究主要就當須估計的投資組合其投入參數具有高維度特質的觀點下，探究因忽略不確定性通膨而對資產配置過程中帶來的估計風險。此研究基於多重群組架構下所發展出的新投資決策法則，能夠確實地評價不確定性通膨對資產報酬的影響性，並在應用於建構大規模投資組合時，能有效減少進行最適化投資決策過程中所需的演算時間與成本。而將此模型應用於建構全球ETFs投資組合的實證結果則進一步顯示，若在均值變異數架構下，因建構大型投資組合時須估計高維度投入參數而伴隨有大量估計風險時，參數估計方式建議結合採用貝氏估計方法來估算資產報酬的一階與二階動差，其所對應得到的投資組合樣本外績效會比直接採用歷史樣本動差來得佳。此實證結果亦隱含：在均值變異數架構下，穩定的參數估計值比起最新且即時的參數估計資訊對於投資組合的績效來得有益。同時，若當投入參數的樣本估計值波動很大時，增加放空限制亦能有利投組樣本外績效。 第二篇文章則主要處理當處於對數常態證券市場下時，投資組合報酬率不具有有限動差並導致無法在均值變異數架構下發展出最適化封閉解時的難題。本研究示範此時可透過漸近方法的應用，有效發展出在具有放空限制下，考量了估計風險後的簡單投資組合配置法則，並且展示如何將其應用至實務上的資產配置過程以建構全球投資組合。本文的數值範例與實證模擬結果皆顯示，估計風險的存在對於最適投資組合的選擇有實質的影響，無估計風險下得出的最適投資組合，不必然是存有估計風險下的最適投資組合。此外，實證模擬結果亦證明，當存有估計風險時，本文所發展的簡單法則，能使建構出的投資組合具有較佳的樣本外績效表現。 / This dissertation consists of two essays on dynamic asset allocation with regard to dealing with estimation risk as being in different uncertainties in the mean-variance framework. The first essay concerns estimation errors from disregarding uncertain inflation in terms of the need in estimating high-dimensional input parameters for portfolio optimization. This study presents simplified and valid criteria referred to as the EGP-IMG model based on the multi-group framework to be capable of pricing inflation risk in a world of uncertainty. Empirical studies shows the proposed model indeed provides a smart way in picking worldwide ETFs that serves well to reduce the amount of costs and time in constructing a global portfolio when facing a large number of investment products. The effect of Bayesian estimation on improving estimation risk as the decision maker is subject to history sample moments for input parameters estimations is meanwhile examined. The results indicate portfolios implementing the Stein estimation and shrinkage estimators offer better performance compared with those applying the history sample estimators. It implicitly demonstrates that yielding stable estimates for means and covariances is more critical in the MV framework than getting the newest up-to-date parameters estimates for improving portfolio performance. Though short-sales constraints intuitively should hurt, they do practically contribute to uplift portfolio performance as being subject to volatile estimates of returns moments. The second essay undertakes the difficulty that the probability distribution of a portfolio's returns may not have finite moments in a lognormal-securities market, and thus leads to the arduous problem in solving the closed-form solutions for the optimal portfolio under the mean-variance framework. As being in a lognormal-securities market, this study systematically delivers a simple rule in optimization with regard to the presence of estimation risk. The simple rule is derived accordingly by means of asymptotic properties when short sales are not allowed. The consequently numerical example specifies the detailed procedures and shows that the optimal portfolio with estimation risk is not equivalent to that ignoring the existence of estimation risk. In addition, the portfolio performance based on the proposed simple rule is examined to present a better out-of-sample portfolio performance relative to the benchmarks.

This work presents model development and model analyses of CO2 storage in deep saline aquifers. The goal has been two-fold, firstly to develop models and address the system behaviour under geological heterogeneity, second to tackle the issues related to problem scale as modelling of the CO2 storage systems can become prohibitively complex when large systems are considered. The work starts from a Monte Carlo analysis of heterogeneous 2D domains with a focus on the sensitivity of two CO2  storage performance measurements, namely, the injectivity index (Iinj) and storage efficiency coefficient (E), on parameters characterizing heterogeneity. It is found that E and Iinj are determined by two different parameter groups which both include correlation length (λ) and standard deviation (σ) of the permeability. Next, the issue of upscaling is addressed by modelling a heterogeneous system with multi-modal heterogeneity and an upscaling scheme of the constitutive relationships is proposed to enable the numerical simulation to be done using a coarser geological mesh built for a larger domain. Finally, in order to better address stochastically heterogeneous systems, a new method for model simulations and uncertainty analysis based on a Gaussian processes emulator is introduced. Instead of conventional point estimates this Bayesian approach can efficiently approximate cumulative distribution functions for the selected outputs which are CO2 breakthrough time and its total mass. After focusing on reservoir behaviour in small domains and modelling the heterogeneity effects in them, the work moves to predictive modelling of large scale CO2  storage systems. To maximize the confidence in the model predictions, a set of different modelling approaches of varying complexity is employed, including a semi-analytical model, a sharp-interface vertical equilibrium (VE) model and a TOUGH2MP / ECO2N model. Based on this approach, the CO2 storage potential of two large scale sites is modelled, namely the South Scania site, Sweden and the Dalders Monocline in the Baltic Sea basin. The methodologies developed and demonstrated in this work enable improved analyses of CO2 geological storage at both small and large scales, including better approaches to address medium heterogeneity. Finally, recommendations for future work are also discussed.

本研究以Stroop中文叫色作業，測驗兒童和成人在Stroop作業之練習和刺激向度分離等情形下，其干擾效果的變化情形。共執行兩個實驗，實驗一中的受試者先接受中性刺激和不和諧刺激的測驗，然後對兩類作業練習8日，其後再測驗一次，探討受試者在練習前、後之干擾效果的變化情形。另一組受試接受實驗二中，中性刺激、整合性不和諧刺激和分離性不和諧刺激等作業的測驗，藉以比較整合性干擾和分離性干擾的差異。兩組受試者皆接受文字閱讀的速度測驗。 結果發現，小學二年級兒童的Stroop干擾效果最大，六年級兒童次之，成人最小，這與之前文獻上所載的研究一致，同時也證實，練習確能降低干擾效果，但仍不能使其完全消失，且練習後，三組受試間的干擾效果已無顯著差異。在實驗二的結果顯著，刺激向度分離的干擾效果仍然存在，但比整合性干擾效果小，且受試者間的分離性干擾也沒有顯著差異。而所有受試的閱讀速度均快於叫色速度。 / The study was used the Stroop Chinese task to examine the course of the Stroop interference among second, sixth grade children and adults. Two experiments were conducted. In experiment I, participants were tested with neutral and incongruent tasks and practiced with the same tasks for the following 8 days. They were tested neutral and incongruent tasks again. Then examined the course of the Stroop interference among children of second, sixth grade children and adults, they were test with neutral and incongruent tasks again. Then examine the course of the Stroop interference in between children and adult during before and after practice. The other group of participants took part in experiment II. They were presented with three tasks consist of neutral, integrated and separated incongruent tasks. Then examine the difference of the interference among children of second, sixth grade and adult during integrated and separated incongruent tasks. Two groups of participants were presented word reading speed of task. The finding of the study was Stroop interference increased from the adults through the sixth grade children and finally to the second grade children is in line with previous finding. We have confirmed that although interference decreases with practice, it is very resistant to eradication. After practice, the interference between children and adults is not significant difference. In the experiment II, it was that separated Stroop stimulus showed interference, and the amount was relatively small. The interference of separated Stroop task among children of second, sixth grade and adults were not significant difference. All participants took longer to name color than to read words.