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Sustainability performance and market risk. A study of the banking sectorSärkiniemi, Arvid, Lindman, Oskar January 2023 (has links)
The financial crisis of 2007-2008 highlighted the societal impacts of bank risk-taking. A strong focus on maximizing profits for shareholders combined with a disregard for, and underestimation of risks led to the downfall of large banks such as Lehman Brothers and multiple other banks getting bailed out by several governments and other banks. The financial crisis spread and impacted all major financial markets across the globe, which highlights the importance of investigating the banking sector from a global perspective. In addition, the influences of corporate social responsibility (CSR) on financial performance and risk have been a growing topic in research as well as in practice. Most banks today invest large amounts of money in CSR activities. The question of how bank spending in CSR activities impacts market risk is important. There are two contradicting views on CSR activities and market risk. The risk mitigation view suggests that banks that focus on stakeholder satisfaction have lower risk due to increased moral capital with stakeholders. The overinvestment view suggests that managers waste scarce resources by overinvesting in CSR activities to further selfish goals and therefore increase risk. This study examines the relationship between sustainability performance (ESG Combined score) and market risk (VaR/CVaR) using a deductive approach. The authors sample 159 banks from 39 countries and all 7 economic regions from 2011-2022. Data is used for testing hypotheses. Results find high ESG Combined Scores are associated with lower VaR/CVaR and results are robust to modifications in VaR/CVaR calculation assumptions. Disaggregation of ESG pillars shows that social pillar scores decrease VaR/CVaR in banks while environmental and governance pillars are insignificant. Results primarily lend support to the risk mitigation view and stakeholder theory stating that firms should focus more on stakeholder satisfaction than maximizing shareholder value. Complementing theories such as legitimacy theory and resources-based view are also considered important theories for explaining the results.
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利用混合模型估計風險值的探討阮建豐 Unknown Date (has links)
風險值大多是在假設資產報酬為常態分配下計算而得的,但是這個假設與實際的資產報酬分配不一致,因為很多研究者都發現實際的資產報酬分配都有厚尾的現象,也就是極端事件的發生機率遠比常態假設要來的高,因此利用常態假設來計算風險值對於真實損失的衡量不是很恰當。
針對這個問題,本論文以歷史模擬法、變異數-共變異數法、混合常態模型來模擬報酬率的分配,並依給定的信賴水準估算出風險值,其中混合常態模型的參數是利用準貝式最大概似估計法及EM演算法來估計;然後利用三種風險值的評量方法:回溯測試、前向測試與二項檢定,來評判三種估算風險值方法的優劣。
經由實證結果發現:
1.報酬率分配在左尾臨界機率1%有較明顯厚尾的現象。
2.利用混合常態分配來模擬報酬率分配會比另外兩種方法更能準確的捕捉到左尾臨界機率1%的厚尾。
3.混合常態模型的峰態係數值接近於真實報酬率分配的峰態係數值,因此我們可以確認混合常態模型可以捕捉高峰的現象。
關鍵字:風險值、厚尾、歷史模擬法、變異數-共變異教法、混合常態模型、準貝式最大概似估計法、EM演算法、回溯測試、前向測試、高峰 / Initially, Value at Risk (VaR) is calculated by assuming that the underline asset return is normal distribution, but this assumption sometimes does not consist with the actual distribution of asset return.
Many researchers have found that the actual distribution of the underline asset return have Fat-Tail, extreme value events, character. So under normal distribution assumption, the VaR value is improper compared with the actual losses.
The paper discuss three methods. Historical Simulated method - Variance-Covariance method and Mixture Normal .simulating those asset, return and VaR by given proper confidence level. About the Mixture Normal Distribution, we use both EM algorithm and Quasi-Bayesian MLE calculating its parameters. Finally, we use tree VaR testing methods, Back test、Forward tes and Binomial test -----comparing its VaR loss probability
We find the following results:
1.Under 1% left-tail critical probability, asset return distribution has significant Fat-tail character.
2.Using Mixture Normal distribution we can catch more Fat-tail character precisely than the other two methods.
3.The kurtosis of Mixture Normal is close to the actual kurtosis, this means that the Mixture Normal distribution can catch the Leptokurtosis phenomenon.
Key words: Value at Risk、VaR、Fat tail、Historical simulation method、 Variance-Covariance method、Mixture Normal distribution、Quasi-Bayesian MLE、EM algorithm、Back test、 Forward test、 Leptokurtosis
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市場風險值管理之應用分析以某金融控股公司為例 / The analysis of Market Risk VaR management :the case of financial holding company周士偉, Chou, Jacky Unknown Date (has links)
2008年次貸風暴橫掃全球金融市場,Basel II制度歷經多年的實施,卻無法有效防阻金融風暴的發生。觀察2008已採用內部模型法之主要國際金融機構之年報,亦發現採用蒙地卡羅模擬法之代表銀行『德意志銀行』於該年度竟發生了35次穿透,市場風險管理到底出了什麼問題?這是被極度關心的現象,產官學界也對此現象提出了許多議題。2012年的現在,次貸的風暴尚未遠去,新的歐債危機也正在蔓延,若金融風暴再次來臨,市場風險管理是否能克服次貸風暴後所凸顯的缺失,市場風險管理的價值除被動管理外,是否還可以進階到主動預警,以作為經營決策的重要參考資訊?這些都是國內金融機構需積極面對的急迫的市場風險管理議題。
個案金控的市場風險管理機制致力於解決次貸以來所凸顯的市場風險管理議題、提升市場風險衡量的精準度、擴大市場風險管理之應用範圍,並將市場風險管理的價值由被動管理角色進階到主動預警角色,以期作為經營決策的重要參考。經過多年的淬煉,其發展理念與經驗應具相當參考價值,故本論文以個案金融控股公司(以下簡稱個案金控)之實務經驗進行個案研究,除分析個案金控市場風險管理機制的基礎架構外,也將研究重心放在個案金控如何在此基礎架構下,開發多種進階市場風險量化管理功能。
本論文除研究個案金控如何完善市場風險值量化機制外,也對各量化功能的實施結果進行分析,以期研究成果可更客觀的作為其他金融控股公司未來發展進階市場風險衡量機制之參考。
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