• Environmental and Resource Economics Review
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• v.19 no.1
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• pp.3-21
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• 2010

By the significant structural change in 1999, a partial privatization has occurred in Korean fossil-fuel power generation sector. Under the current price scheme wholesale electricity price is dependent on output size, and hence, may not satisfy the assumption of price-taking producers. The purpose of our study is constructing the productivity change measurements of Korean power generation sector taking into account possibly imperfect competition and variable returns to scale. Our approach based on Harrison (1994) and Levinsohn (1993) derives the plant-level productivity measurements of the period between 2001 and 2007, as well as the measurements of mark-ups and returns to scale. It is shown that the mark-up size is dependent on the plants' fuel type and is decreasing over time. Allowing for imperfect competition and variable returns to scale adjusts the productivity measurements substantially.

• Industrial Engineering and Management Systems
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• v.8 no.1
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• pp.1-13
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• 2009

This paper presents a coordinated planning model of price-dependent demand for a single-manufacturer and a single-retailer. The demand is assumed to be normally distributed, with its mean being price dependent. The manufacturer and retailer coordinate with each other to jointly and simultaneously determine the retail selling price and the retailer order quantity to maximize the joint expected total profit. This model is then compared to a 'returns' policy model where manufacturer buys back unsold items from the retailers. It is shown that the optimal total profit is higher for coordinated planning model than that for the returns policy model, in which the retail price is set by the retailer. A compensation or profit sharing scheme is then suggested and it is shown that the coordinated model with profit sharing yields a 'win-win' situation. Numerical results are presented to illustrate the profit patterns for both linear and nonlinear demand functions. The coordinated planning model, in addition, has a lower optimal price than for a returns policy model, which would result in higher sales, thus expanding the markets for the whole supply chain.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.12
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• pp.1-7
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• 2021

The study examines the influence of COVID-19 on the stock market returns of Saudi Arabia. The data was analyzed through event study methodology using daily price data of Tadawul All Share Index (TASI). The study examines the behavior pattern of the Saudi Arabian stock market in different phases during the event period by selecting six-event windows with a range of 10 days. The results report a negative Abnormal Return (AR) of -0.003 on the event date, while the abnormal returns reversed the next day to 0.005 positively. The result of Cumulative Abnormal Return (CAR) is negative and significant at the 1 percent level in all the six-event windows starting from the event date to day 59 after the event for the TASI index. Even though the influence of the COVID-19 pandemic decreased after 30 days of the event date, it increased during the last ten days of the event window. The stock market volatility of Saudi Arabia increased during the post-event period compared to the pre-event period with a negative mean return of -0.326 and a greater standard deviation. In a conclusion, the study found a significant influence of the COVID-19 pandemic on the stock market returns of TASI.

• Journal of Industrial Convergence
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• v.7 no.1
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• pp.63-82
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• 2009

Many The purpose of this paper is to revisit the existence of monthly effect in the Korea Stock Market. We conducted additory test about KOSPI200 from January 1990 to December 2002 and about KOSDAQ from January 2002 to December 2006. The other main focus is examine Size Effect in Korean Stock Market. We also indicate Information hypothesis throught our findig. Data used in this paper are monthly returns of KOSPI and KOSDAQ from 1980 to 2006. As a result, Evidence is provided that monthly abnormal returns in January have large means relative to the remaining eleven months. The relation between abnormal returns and size is always negative and more pronounced in January than in any other month-even in years. More than fifty percent of the January premium is attributable to large abnormal returns during the first week of trading in the year particularly on the first trading day. This finding is highly significant in the mall sized capital stock of KOSPI market. We found January effect and Size Effect in the KOSPI market, but we didn't find January effect and Size Effect in the KOSDAQ market and KOSPI200.

• Communications for Statistical Applications and Methods
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• v.28 no.1
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• pp.59-79
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• 2021

Value at Risk (VaR) is one of the most common risk management tools in finance. Since a portfolio of several assets, rather than one asset portfolio, is advantageous in the risk diversification for investment, VaR for a portfolio of two or more assets is often used. In such cases, multivariate distributions of asset returns are considered to calculate VaR of the corresponding portfolio. Copulas are one way of generating a multivariate distribution by identifying the dependence structure of asset returns while allowing many different marginal distributions. However, they are used mainly for bivariate distributions and are not widely used in modeling joint distributions for many variables in finance. In this study, we would like to examine the performance of various copulas for high dimensional data and several different dependence structures. This paper compares copulas such as elliptical, vine, and hierarchical copulas in computing the VaR of portfolios to find appropriate copula functions in various dependence structures among asset return distributions. In the simulation studies under various dependence structures and real data analysis, the hierarchical Clayton copula shows the best performance in the VaR calculation using four assets. For marginal distributions of single asset returns, normal inverse Gaussian distribution was used to model asset return distributions, which are generally high-peaked and heavy-tailed.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.4
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• pp.325-332
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• 2022

This research aims to examine and assess how management methods, financial conditions, and corporate governance strategies affect stock returns. This study employs a quantitative approach with a population of 1968 firms with stock returns (return) and a sample of 225 companies with corporate governance practices in the manufacturing industry in Indonesia from 2013 to 2018. The findings of this study show that strategic management has a significant impact on stock return, financial condition, and corporate governance strategy. The findings of this study on debt strategy as a proxy for management strategy, debt default as a proxy for economic conditions, corporate governance strategy as a proxy for centralized ownership, and independent commissioners function as a mechanism of internal and external control in increasing stock return for investors all support increasing stock return for investors. The cost reduction strategy includes reducing operating costs unless the audit committee has not yet functioned as an internal control or requirement for a company to be listed with the Financial Services Authority on the Indonesia Stock Exchange.

• Korean Journal of Organic Agriculture
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• v.29 no.1
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• pp.41-50
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• 2021

This paper analyzes the efficiency of social enterprises by analyzing bootstrapping data envelopment analysis. Unlike the definitive DEA model, we analyze the confidence intervals of efficiency estimates through the DEA model, which takes into account stochastic factors. Major analysis results are summarized as follows: First, the results of the bootstrapping DEA analysis of social enterprises estimated that the technical efficiency was 0.459 and the 95% confidence interval was 0.389 to 0.601. Second, the number of inefficient social enterprises with efficiency values of less than 0.5 was found to be 15 (55.56%) in technical efficiency, 5 (18.52%) in pure technical efficiency, and 8 (29.63%) in scale efficiency. It can be seen that a significant number of social enterprises are operating in an inefficient state. Third, looking at the returns of scale of social enterprises, 25 (67.57%) are currently in the increasing returns of scale, 10 (27.02%) are in the constant returns of scale, and 2 (5.41%) are in decreasing returns of scale. In other words, it can be seen that social enterprises are under-invested in terms of input factors.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.9
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• pp.105-114
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• 2022

Financial markets have long been known to be prone to behavioral biases. One such behavioural bias that is consequential yet pervasive in financial markets is the herd effect. The objective of this study is to determine whether or not there exist herd behaviour in the new and bourgeoning Decentralized Finance (DeFi) Tokens market. This is accomplished by using daily returns of 22 DeFi tokens from January 29, 2017 to August 19, 2021, and the Cross-sectional Absolute Deviation (CSAD) of market returns to capture herd behavior. The results fail to provide any evidence of herding in the DeFi token market on bullish days, that is days for which the average market returns is positive. For bearish days however, that is days for which the market returns is negative, our empirical findings point to the presence of adverse herding in the DeFi token market. This phenomenon can be explained to some extent by the investor composition of the DeFi market. The DeFi token space is a growth market dominated by experts and/or enthusiasts who are insulated against the temptation and panic of negative market swings by the level of market and technical information they possess on the assets they invest.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.5
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• pp.41-51
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• 2022

The research looks into the impact of stock split announcements on stock prices and market efficiency in the Colombo Stock Exchange (CSE). This research uses a sample of 26 stock split announcements that occurred between 2020 and June 2021. According to the Global Industry Classification Standards, the stock split announcements covered in the study pertain to 26 businesses and 9 industries (GICS). To obtain the results, the usual event research methodology is used. The findings demonstrate significant average abnormal returns of 15.01 percent on the day the stock split news is made public and abnormal returns of 4.11 percent and -4.05 percent one day before and after the stock split announcement date, respectively. The study's findings revealed significant positive abnormal returns one day before the disclosure date, indicating information leakage, and significant negative abnormal returns the next day after the announcement date, indicating CSE informational efficiency. Because stock prices adapt so quickly to public information, these findings support the semi-strong form efficient market hypothesis, which states that investors cannot gain an abnormal return by trading in stocks on the day of the stock split announcement.

• Asia-Pacific Journal of Business
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• v.13 no.4
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• pp.79-89
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• 2022

Purpose - The purpose of this study was to examine the impact of ESG rating changes of companies listed in Korean Stock Exchange on stock returns. Design/methodology/approach - This study collected prices and ESG ratings of all the companies listed on the Korea Composite Stock Price Index. Based on yearly change of ESG ratings we grouped companies as 2 portfolios(upgrade and downgrade) and calculated portfolios' return. Findings - First, the difference in returns between upgraded and downgraded portfolios is small and statistically insignificant. Second, however, in the COVID-19 period (2020 ~ 2021), the upgraded portfolio outperforms the downgraded portfolio by 0.7 percentage points per month. The difference in returns between upgraded and downgraded portfolios is statistically significant after controlling for the Carhart four factors. Lastly, there are much higher volatility when the ESG rating changes are made of companies with low levels of ESG ratings. Research implications or Originality - This study is the first to examine the impact of ESG rating changes on stock returns in Korea. Furthermore, the findings can serve as a reference for managers who want to control a firm's risk by ESG rating changes. Practically, asset managers can use the findings to construct portfolios that are less risky or more profitable than the market portfolio.