Mehmet F. Dicle and Kendra Reed
As investors’ fear has an impact on their risk-return tradeoff, this fear leaves markets susceptible to sudden and large fluctuations. The purpose of this study is to suggest…
Abstract
Purpose
As investors’ fear has an impact on their risk-return tradeoff, this fear leaves markets susceptible to sudden and large fluctuations. The purpose of this study is to suggest regulators to amend their precautionary methods to recognize the difference in investor behavior for high-risk periods versus low-risk periods.
Design/methodology/approach
The authors empirically show the difference in investor response to changes in expected risk as a function of level of risk. They then show different return patterns for high-risk and low-risk days. Their approach is implemented to evaluate whether investors’ reaction is the same to changes in risk during high-risk versus low-risk periods.
Findings
The results indicate that the negative return response to incremental increases in risk is significantly higher for periods of high versus low expected risk, with high defined as risk levels above long-run normal.
Research limitations/implications
Investors’ increased response to changes in risk exposes financial markets to higher likelihood of sudden and larger fluctuations during high-risk periods. Regulator-imposed circuit breakers are designed to protect markets against such market crashes. However, circuit breakers are not designed to account for investor behavior changes. The results show that circuit breakers should be different for high- versus low-risk periods.
Practical implications
A circuit breaker that is designed to protect investors against large drops should be amended to have a lower threshold during high-risk periods.
Originality/value
The contribution is, to the authors’ knowledge, the first research effort to evaluate the effects of differences in investor behavior on investor reactions and regulator imposed fail-safes. During the times of extreme market risk, the proposed changes may enable circuit breakers function their intended purposes.
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Rachel Sayers, John Levendis and Mehmet Dicle
The purpose of this paper is to determine the nature of the wage gap between genders and sexual orientation.
Abstract
Purpose
The purpose of this paper is to determine the nature of the wage gap between genders and sexual orientation.
Design/methodology/approach
The paper uses OLS on pooled repeated cross-sections.
Findings
The differences in wages between gay/straight men and women mirror what would be expected from labor force attachment more so than direct heterosexism.
Research limitations/implications
The authors use a functional definition of sexual preference that reflects whether the respondent had sex with someone of the same gender in the same year. It does not ask whether the person identifies publicly as gay/lesbian/bisexual.
Originality/value
The authors verify and extend earlier findings on the sexual orientation and gendered wage gap.
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Mehmet F. Dicle and John Levendis
The purpose of this paper is to hypothesize two channels in which market volatility affects initial public offering (IPO) activity.
Abstract
Purpose
The purpose of this paper is to hypothesize two channels in which market volatility affects initial public offering (IPO) activity.
Design/methodology/approach
First, CEOs time the market for IPOs and volatility makes this decision process harder. Second, risk-averse IPO investors become more reluctant toward IPOs during periods of higher volatility for their after-IPO returns.
Findings
The authors provide evidence that higher market volatility leads to lower IPO activity, supporting these hypotheses. More importantly, the authors show that it is not the realized volatility, but rather the implied (expected) volatility, that causes lower IPO activity.
Research limitations/implications
While there may be many companies that are ready to have IPOs, they may be simply waiting for a more opportune time which may not necessarily be a period of high prices but of low volatility.
Practical implications
The public policy prescription is clear: if IPOs are to be encouraged, then regulatory policies should be constructed with the aim of reducing volatility.
Originality/value
This study is the first (to the authors’ knowledge) to argue that it is not the realized volatility which most affects the IPO decisions of executives, entrepreneurs and investors.
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Khaled Abdou and Mehmet F. Dicle
The purpose of this paper is to investigate whether all of the risk factors were priced during the internet bubble period.
Abstract
Purpose
The purpose of this paper is to investigate whether all of the risk factors were priced during the internet bubble period.
Design/methodology/approach
A unique hand collected dataset was used from public prospectuses for companies that issued an initial public offering during the internet bubble period. Three hypotheses were proposed: the risk factors mentioned in the prospectus are important for IPO trading and therefore affect IPO underpricing; risk factors affect the IPO deal attributes; and the number of risk factors cited by the issuing firm is affected by direct participants such as venture capitalists and investment bankers.
Findings
It was found that hi‐tech dummy played a significant role during the bubble period. Moreover, not all risk factors are regarded important, some of them are not significant at all as predicted by first hypothesis. The most striking observation is the negative economic significance of the risk factor no prior market for the traded stock. This reveals that, traders are selective in valuing risks and may value some factors as opportunities and not as risk factors. In addition, the results reveal that risk factors do affect the deal attributes as predicted by our second hypothesis. Also, the pricing of these risk factors are not different between retail and hi‐tech companies. Regarding the participants, it was found that venture capitalists and investment bankers have a significant statistical and economic effect on the number of risk factors reported in the prospectus.
Originality/value
The paper contributes to the literature by investigating the IPO underpricing phenomenon in the internet bubble period.
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The purpose of this study is to determine and compare the total and per passenger HC, CO, NOx and CO2 emissions from aircraft landing and takeoff (LTO) cycle before and during the…
Abstract
Purpose
The purpose of this study is to determine and compare the total and per passenger HC, CO, NOx and CO2 emissions from aircraft landing and takeoff (LTO) cycle before and during the COVID-19 pandemic. In addition, it is aimed to determine the global warming potential (GWP), environmental impacts (EIs) and enviroeconomic cost (eco-cost) of these emissions in total and per passenger.
Design/methodology/approach
Analyses were carried out with the help of the International Civil Aviation Organization’s Engine Emission Databank, using real flight data recorded by the airport authority.
Findings
During the COVID-19 pandemic, total pollutant emissions (HC, CO, NOx and CO2) decreased between 23.7% and 30.8% compared with the pre-pandemic period. In addition, per passenger pollutant emissions increased during the pandemic. Compared with the pre-pandemic period, GWP, EI and eco-cost values decreased by 24.1%, 23.89% and 23.93%, respectively, in the pandemic. However, the per passenger GWP, EI and eco-cost values increased by about 10% compared with the pre-pandemic period.
Practical implications
This study reveals the effects of COVID-19 in terms of EIs and environmental costs caused by aircraft in the LTO cycle.
Originality/value
The originality of this study is to calculate the pollutant emissions caused by aircraft in the LTO cycle with real flight data and to reveal the effects of the COVID-19 pandemic. The novelty of this study is the determination and comparison of total and per passenger pollutant emissions, GWP, EI and eco-cost before and during the pandemic.
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The purpose of this paper is to calculate the fuel consumption and emissions of carbon monoxide (CO), nitrogen oxide (NOx) and hydrocarbons (HC) in the taxi-out period of aircraft…
Abstract
Purpose
The purpose of this paper is to calculate the fuel consumption and emissions of carbon monoxide (CO), nitrogen oxide (NOx) and hydrocarbons (HC) in the taxi-out period of aircraft at the International Diyarbakir Airport in 2018 and 2019.
Design/methodology/approach
Calculations were performed by determining the engine operating times in the taxi-out period with the flight data obtained from the airport authority. In the analyses, aircraft series and aircraft engine types were determined, and the Engine Exhaust Emission Databank of the International Civil Aviation Authority (ICAO) were used for the calculation.
Findings
Total fuel consumption in the taxi-out period in 2018 and 2019 was calculated as 525.64 and 463.69 tons, respectively. In 2018, HC, CO and NOx emissions caused by fuel consumption were found to be 1,109, 10,668 and 2,339 kg, respectively. In 2019, the total HC, CO and NOx emissions released to the atmosphere during the taxi-out phase are 966, 9,391 and 2,126 kg, respectively. B737 Series aircraft have the largest share in total fuel consumption and pollutant emissions.
Practical implications
This study explains the importance of determining fuel consumption and pollutant emissions by considering engine operating times in the taxi-out period. The study provides aviation authorities with scientific methods to follow in calculating fuel consumption and emissions from aircraft operations.
Originality/value
The originality of this study is the calculation of fuel consumption and pollutant emissions by determining real-time engine running times in the taxi-out period. In addition, calculations were made with real engine operating times determined in the taxi-out period using real flight data.
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Mehmet Kadri Akyüz, Hasim Kafali and Onder Altuntas
This paper aims to measure the thermal comfort conditions and indoor air quality parameters, through on-site measurements taken in the areas mostly occupied by the passengers and…
Abstract
Purpose
This paper aims to measure the thermal comfort conditions and indoor air quality parameters, through on-site measurements taken in the areas mostly occupied by the passengers and airport staff. Terminal buildings consist of areas with various functions. Heating, ventilation and air conditioning requirements vary from area to area, thus leading to challenges in the management of indoor environment quality. Therefore, the study focuses on investigating the indoor environment conditions in various areas of the terminal buildings.
Design/methodology/approach
In this study, the thermal comfort and indoor air quality were evaluated based on the parameters [CO2 concentration, relative humidity, temperature, predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD)] collected for summer 2019 from different zones inside the International Dalaman Airport terminal building located in the southwest of Turkey. The measurements were performed in the areas mostly occupied by the airport staff and passengers (check-in area, security control areas, international departure lounge, domestic departure lounge and baggage claim hall).
Findings
As a result of the study, it was observed that the CO2 concentration was 480–965 ppm, the relative humidity was 51.9–75.8% and the temperature was in the range of 23.9°C–28.3°C inside the airport terminal. The PMV values were determined to be in the range of −0.23 to 0.67, and the PPD values 5–15%, which are used to measure the thermal comfort conditions.
Originality/value
There has been limited study on the determination of the indoor air quality in airport terminals and the investigation of the thermal comfort conditions. However, in this study, indoor air quality and thermal comfort conditions were determined by on-site measurements in the five mostly occupied areas by passengers and employees in the terminal building.
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Safak Kaya, Esref Arac, Fethiye Akgul, Senol Comoglu, Sehmuz Kaya, Songul Araç, Yesim Yildiz, Seyit Ali Buyuktuna, Bircan Kayaaslan, Emine Parlak, Birol Baysal, Faruk Karakecili, Elif Zelal Balik, Ali Akkoç, Kevser Ozdemir, Seyhmus Kavak, Suat Ali Dogan, Emrah Günay, Semsi Nur Karabela, Mehmet Cabalak, Yasemin Cag, Veli Avci, Yasemin Durdu, Zehra Kaya, Damla Kilic, Halis Yerlikaya, Hüseyin Tarakçı, Osman Mentes, Ayse Sağmak Tartar, Adem Kose, Omer Faruk Alakus, Ulas Aktas, Halil Komek and Selcuk Aksoz
This paper aims to determine the knowledge and attitudes of the physicians regarding human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS), to emphasize…
Abstract
Purpose
This paper aims to determine the knowledge and attitudes of the physicians regarding human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS), to emphasize that these patients exist and they will exist in the future and to raise awareness so as to prevent that their rights to treatment are revoked.
Design/methodology/approach
The survey was conducted via a link sent through an online system. Random physicians from 81 cities of the country were invited to the survey. The survey has 41 questions regarding knowledge and attitudes in total, including epidemiological information such as age, gender and title.
Findings
A total of 3,107 physicians has voluntarily participated in the study. In total, 2,195 (70.7%) are internal physicians and 912 (29.3%) are surgical physicians among the participant physicians. In total, 1,452 (46.7%) of the participants are specialist physicians, 608 (19.6%) of the participants are practising physician and the rest of it is physician assistants, academicians and dentists, respectively.
Originality/value
In this study, it has been found out that the physicians have a lack of knowledge on HIV/AIDS and they adopt a discriminatory attitude towards HIV-positive persons. HIV-positive patients who are exposed to discrimination and scared of being uncovered refrain from applying to hospitals for treatment, which puts public health into jeopardy due to the high viral load and these patients are faced with difficulties in coping with both medical and emotional load of the disease.
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Hasan Alma and Mehmet Baha Karan
This paper is aimed to evaluate recently privatized 18 electricity distribution and retail companies, using the data and conditions at the time they were privatized. The main…
Abstract
Purpose
This paper is aimed to evaluate recently privatized 18 electricity distribution and retail companies, using the data and conditions at the time they were privatized. The main hypothesis of the study is that most of the privatized companies in this research are underpriced similar to previous experiences in developed and emerging economies.
Design/methodology/approach
Values of the companies are calculated considering the formal procedures of Turkish energy authorities. These companies are valued under the base, moderate and extreme scenarios created from different sets of assumptions considering conditions and existing data at the time they were privatized. Discounted cash flows (DCF) methodology is used in the estimations. The market prices obtained in their privatization tenders are compared with those theoretically calculated values (intrinsic prices).
Findings
The findings reject the hypothesis and indicate an overpricing in general in the privatizations of Turkey. Even the extreme scenario which gives the highest intrinsic values supports the findings.
Research limitations/implications
Research is limited with 18 regional electricity distribution company in Turkey.
Originality/value
The paper is one of the initial empirical studies on the valuation of energy companies using DCF methodology in an emerging market.
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Mehmet Özdemir, Sedat Sünter and Bilal Gümüs5
In this study, a single‐phase induction motor with constant v/f, fed by matrix converter, is considered under various frequencies. The modeling of the motor, mechanical load for…
Abstract
In this study, a single‐phase induction motor with constant v/f, fed by matrix converter, is considered under various frequencies. The modeling of the motor, mechanical load for single phase induction motor and matrix converter have been obtained by using Simulink package program. The performance of the motor under various frequencies is determined. A single‐phase induction motor considered in this work has a running capacitor. The analysis and simulation results are presented.