論文把國內十家公股銀行的放款違約資料進行合併，並且以合併後的資料，使用 CreditPortfolioView 模型建立整體公股銀行放款組合的損失分配，利用公股銀行的放款資料，探討曝險分組對於損失分配(loss distribution)的影響，並且使用重點抽樣(Importance Sampling)的方法估計風險貢獻(risk contribution, RC)，利用給定部份系統風險因子的模型，進行壓力測試(stress test)。 由本論文的實證結果可以發現同一類放款產品曝險之中，若是個別曝險有極端的曝險額，將會增加此類產品的集中度風險。若曝險總額固定，但是曝險筆數較少，每筆曝險佔總曝險的比例較大，也會產生較大的集中度，而有較大的風險值(valut at risk, VaR)、預期短缺(expected shortfall, ES)及經濟資本(economic capital, EC)，因此曝險額的設定愈粗略，將會估出較高的未預期損失。 本論文使用重點抽樣的方法，估算預期短缺的風險貢獻。並且由實證的結果， 觀察到同一類放款的經濟資本率和放款曝險額呈現正相關並且具有接近線性的關係，因此可以建立經濟資本率的線性估計式，對未來可能的放款，進行簡單的風險貢獻及經濟資本的估算。 要進行壓力測試，最大的問題是必須選擇適當的施壓變數及設定可能的逆境值(downturn values)。我們通常選擇具有經濟意含的總體因子，當作施壓變數。但是逆境值的設定，可能是主觀認定或者參考歷史資料，如果要設定多個總體因子逆境值，很容易忽略了總體變數之間的關係。本論文嘗試使用常態分配及條件常態分配的假設， 建立可能發生的壓力情境，並且利用給定部份系統風險因子的模型，進行壓力測試。

近年來金融市場情勢瞬息萬變且波動劇烈而令投資人難以捉摸，導致被動式投資重獲投資人的青睞。市值加權法是最普遍被使用的指數編製方法，傳統市值加權指數的缺點，主要有投資組合主要集中於特定成份股與暴露於不會吸引風險溢價的各類風險因子中，這些缺點促成Smart Beta策略的發展，未來將有許多具備不同風險與報酬水準的指數供投資人參考。本研究選用近幾年提出不需仰賴預期報酬假說的等量風險貢獻度投資組合(ERC)建構方式，以台灣50為基準，利用其成份股建構投資組合，探討權重與風險分散特性，並且檢視其績效表現與報酬風險輪廓。為了有比較上的基礎，除了與台灣50做比較外，也另外選用以風險分散角度所配置的投資組合建構方法：等權重投資組合(EW)作對照。 　　研究結果發現全樣本時期，等量風險貢獻度投資組合在事後相較於台灣50擁有較低的波動度。當市場趨勢向下時，除了能維持其低波動的特性，還能提供某種程度上的抗跌能力。然而，以報酬率和Sharpe Ratio指標來看，表現皆不如台灣50，但優於等權重投資組合。同時，依不同經濟狀況與時間區間檢視投資組合績效表現，等量風險貢獻度投資組合能將波動度控制在較低水準，但績效表現上較不穩定。 　　本文透過HHI指數及吉尼係數衡量持股集中度與風險集中度。以持股權重分配的特性來說，台灣50極端集中於少數股票上，等量風險貢獻度投資組合和等權重投資組合則相對較平均。以風險權重分配的特性來說，台灣50風險權重過於集中，風險權重較平均分散的組合則為等量風險貢獻度投資組合。 / Traditional capitalization-weighted approaches are the most common ways to construct indexes. However, during market up turns, the capitalization-weighted indexes may be influenced by a small number of large-cap stocks. Smart beta indexes have recently prompted great interest among academic researchers and market practitioners. Risk-based indexes are an important category of smart beta. In this article, we explore equal risk contribution portfolio (ERC), which is risk-parity based smart beta. The portfolio implies to determine the weights so as to obtain the same risk contribution for each asset. The aim is to minimize the concentration in terms of risk contributions. In this paper, we examine whether or not ERC portfolio can outperform a buy and hold, capitalization-weighted and equally-weighted allocation in different economic environments. We also compute the parity in portfolio “risk allocation” and parity in “asset class allocation” using HHI index and Gini coefficient. 　　We consider here real-life applications with stock universe: the Yuanta /P-shares Taiwan Top 50 ETF. We compute smart beta portfolios by using the one-year empirical covariance matrix of stock returns. Empirical applications show that ERC portfolios generally are inferior in terms of return performance and Sharpe ratios. It does have some characteristics such as balanced risk allocation and less volatile performance characteristics. It also exposes to lower maximum drawdown. ERC portfolio provides the best ex ante and ex post “parity “in asset class risk contribution. On the other hand, the capitalization-weighted portfolio is concentrated in terms of weights and risk contributions. The statistics suggest to us that the capitalization-weighted portfolio’s superior Sharpe ratio is largely due to its higher returns.

截至2016年的統計資料，我國產險與壽險業的保險公司家數來到54家，保險業資產總額佔了全台灣所有金融機構總資產的31.78%，資產規模來到新台幣22.6兆元，在如此龐大的資產規模下，保險公司的投資組合管理變成相當的重要，重點漸漸的從投資在什麼樣的商品可以讓資金獲取最大效益轉移到了投資後的管理與部位的調整，以避免不必要的非系統性風險，有鑑於此，台灣在2003年實施了RBC制度，讓保險公司的投資組合的分配有所依據，不過仍然免不了過度集中在某些資產的問題，所以本研究的目的在於能否運用風險集中度的概念來判斷投資組合是否過度集中，而不僅僅只有投資金額的比例來做判斷。 本論文的研究方法會根據各家保險公司的實際投資組合以每半年或每年的型式分別計算Marginal Risk Contribution(MRC)的値，並且進行分析後再以Herfindahl-Hirschman Index(HHI)與 Gini Index 來檢視長期資產組合集中度的趨勢，最後的研究結果可以發現若是從邊際風險貢獻的比例來看，各保險公司的風險分布主要是集中在國內上市普通股與ETF、海內外不動產投資、國外已開發國家或新興市場上市普通股與ETF以及A評等的國外固定收益債券，而利用HHI與Gini Index兩個指標來看，各保險公司的資產集中度是逐年上升的。 / According to the statistical data in 2016, there are 54 insurance companies which includes property and casualty insurance company and life insurance company. And the scale of insurance asset is NTD 2,260 billion, accounting for 31.78% of whole asset of financial institution in Taiwan. Under huge amount of asset, the portfolio management for insurance company become more and more important. The key points of this issue are transferring to the ratio of portfolio management from choosing asset class to get maximum profit in order to avoid the nonsystematic risk gradually. Therefore, the Risk-based Capital policy has established in 2003 in Taiwan. The ratio of the insurance companies’ portfolio had the reference to allocate. However, there were some issues about the excessive concentration of some asset classes. So, the target of this study is using the concept of the risk concentration to judge the portfolio too concentrated or not. Not just judge it by its amount invested. The research process of this thesis is to calculate the marginal risk contribution value of the insurance companies’ portfolio every half a year or every year. Moreover, using the Herfindahl-Hirschman Index (HHI) & Gini Index to observe the trend of long term portfolio concentration. From the marginal risk contribution ratio. We can found the result of this study is the risk concentrated on the domestic listed common stock & ETF, domestic or foreign Real Estate, foreign developed market or emerging market listed common stock & ETF and fixed income bond (A rating). Besides, using the Herfindahl – Hirschman index and Gini index. The concentrated ratio of insurance companies’ portfolio were raising recent years.