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How do stock prices evolve over time? The standard assumption of geometric Brownian motion, questionable as it has been right along, is even more doubtful in light of the recent stock market crash and the subsequent prices of U.S. index options. With the development of rich and deep markets in these options, it is now possible to use options prices to make inferences about the risk-neutral stochastic process governing the underlying index. We compare the ability of models including Black–Scholes, naïve volatility smile predictions of traders, constant elasticity of variance, displaced diffusion, jump diffusion, stochastic volatility, and implied binomial trees to explain otherwise identical observed option prices that differ by strike prices, times-to-expiration, or times. The latter amounts to examining predictions of future implied volatilities.

Certain naïve predictive models used by traders seem to perform best, although some academic models are not far behind. We find that the better-performing models all incorporate the negative correlation between index level and volatility. Further improvements to the models seem to require predicting the future at-the-money implied volatility. However, an “efficient markets result” makes these forecasts difficult, and improvements to the option-pricing models might then be limited.

In this chapter we develop and implement a method for maximum simulated likelihood estimation of the continuous time stochastic volatility model with the constant elasticity of volatility. The approach does not require observations on option prices, nor volatility. To integrate out latent volatility from the joint density of return and volatility, a modified efficient importance sampling technique is used after the continuous time model is approximated using the Euler–Maruyama scheme. The Monte Carlo studies show that the method works well and the empirical applications illustrate usefulness of the method. Empirical results provide strong evidence against the Heston model.

The topic of volatility measurement and estimation is central to financial and more generally time-series econometrics. In this chapter, we begin by surveying models of volatility, both discrete and continuous, and then we summarize some selected empirical findings from the literature. In particular, in the first sections of this chapter, we discuss important developments in volatility models, with focus on time-varying and stochastic volatility as well as nonparametric volatility estimation. The models discussed share the common feature that volatilities are unobserved and belong to the class of missing variables. We then provide empirical evidence on “small” and “large” jumps from the perspective of their contribution to overall realized variation, using high-frequency price return data on 25 stocks in the DOW 30. Our “small” and “large” jump variations are constructed at three truncation levels, using extant methodology of Barndorff-Nielsen and Shephard (2006), Andersen, Bollerslev, and Diebold (2007), and Aït-Sahalia and Jacod (2009a, 2009b, 2009c). Evidence of jumps is found in around 22.8% of the days during the 1993–2000 period, much higher than the corresponding figure of 9.4% during the 2001–2008 period. Although the overall role of jumps is lessening, the role of large jumps has not decreased, and indeed, the relative role of large jumps, as a proportion of overall jumps, has actually increased in the 2000s.

The integration of the urban people to the city is on the one hand the integration of the physical and natural structure of the city with human element, and on the other hand, integration of urban people with each other by acquiring urban culture. City streets are mostly inhabited by street residents, which include street vendors, who sell products changing from food to textile, arts and crafts or music in an affordable price to city dwellers, and also people who, for economical, psychological or sociological reasons, live in the streets such as beggars and homeless people. If the spirit of a city can exist within the common production and living space of the people who make that city, then it means that the cities lose their souls to exclude those who choose to live on the streets or those who earns their living on the street. If no one can exist without the other, then the existence of the mainstream labour market of the city would only be possible by accepting street residents, whether the ones who choose to live in the streets or earns a living in the streets, who it has marginalised by ignoring and pushing outside the orthodox norms of the city life.

The Covid-19 pandemic, which started in China and spread rapidly all over the world in a short time, can be considered as a dynamic struggle that forces all individuals and therefore organizations to act with new strategies. When considered in terms of its effects and consequences, it can even be regarded as the beginning of a new world order. In this new order, individuals who are unintentionally exposed to chaos theories and possible disaster scenarios related to Covid-19, both in their daily life and in organizational life, can make an effort to continue their lives with the increase in their anxiety levels. While this new order, which shakes the vital balance, forces individuals to struggle, the managers of the organization become a part of this struggle. In addition to the individual struggles of the employees, organizations are also in a separate struggle as providing the necessary support. In this chaos environment, it is important that the psychological health of the employees and the strategic moves of the organizations are mutually supportive in order to ensure a healthier working life. Therefore, this research was carried out with the support of current data and literature to evaluate the Covid-19 pandemic under the headings of remote work, work−family balance and the psychological reflections they cause. In this context, the changes caused by covid-19 were evaluated from the employee’s point of view, and inferences were made from the possible consequences of the situation.

Changes and transformations experienced today have created alternative lifestyles in cities. Many life concepts try to find solutions to environmental problems, so much so that this section focuses on smart eco-city concept, which is one of the trending city initiatives of the last century and is expected to become more popular each day. In the chapter, firstly, information about the concepts of eco-city and smart city is given and then what is meant by the concept of smart eco-city is discussed. Next, smart eco-cities have been tried to be explained with application examples. Finally, the chapter emphasizes the importance of ecological cities blended with technology for the sustainability of living spaces and offers implications for future research.

The purpose of this study is to provide preliminary insights into the relationships between self-monitoring, emotional expressivity, emotional labor, felt leader authenticity, and authentic leadership (AL) within a unique context – West Texas Baptist congregations. Using a sample of 40 Baptist pastors, we employed survey research methods and correlational analyses to explore the focal relationships. Our results revealed that self-monitoring is positively correlated with surface acting, yet negatively associated with AL, within our sample of West Texas Baptist pastors. Emotional expressivity is negatively related to surface acting, but not deep acting, and positively related to genuine emotional displays. We also found that surface acting is negatively associated with genuine emotion displays and felt authenticity, while felt authenticity and AL are positively correlated. However, no relationships between self-monitoring, deep acting, felt authenticity, and AL were revealed. Thus, we identified cases where leader authenticity may be threatened within an organizational context with strong emotional display rules, suggesting a boundary condition for AL. Additionally, we advance propositions gleaned from our research regarding the influence of the omnibus (e.g., community religiosity) and discrete context on leader emotional labor and authenticity. We conclude with practical recommendations for leaders seeking to balance authenticity with emotional display rules associated with unique roles and contexts, as well as recommendations for scholars seeking to conduct research in such settings. We also provide candid insights regarding the challenges we encountered in researching leader authenticity within a highly religious context.

With the rapid development of technology in the era of digitalization, Industry 4.0 has become a reference for R&D studies in various sectors. The rapid development of technology makes the life of societies and people easier. For this reason, governments tend to develop their technologies and to encourage organizations in this field for this purpose. The concept of Industry 5.0 or Society 5.0 explains the revolution in people's lives with the development of the Fourth Industrial Revolution. Today, many interrelated factors are rapidly preparing people for a complex and volatile future. This situation is accepted as the “new normal” and is defined as VUCA-RR (Volatility, Uncertainty, Complexity, Ambiguity, Rapidity, Radicality). Variability refers to the increasing pace of change, uncertainty, unpredictability in life. Complexity indicates difficulties in relationships in life, and ambiguity indicates difficulties in understanding the events around us. The advancement and widespread use of digital technologies will enable organizations to develop sustainable strategies by providing them with the opportunity to grow by achieving sustainable competitiveness and profit in the VUCA-RR environment.

Generation Z refers to those born during a time when the internet and technology were available to practically everyone in education, social life and employment. Because Generation Z was born during a period of rapid technical growth and digital transition, it is also known as the ‘Digital Generation’. Digitalization is one of the developments that best symbolizes the twenty-first century, and it has both benefits and drawbacks. Because of its strong link with digitization, Generation Z is seen as the generation that experiences these benefits and drawbacks the most intensely. For this reason, the disadvantages as well as the advantages it provides to Generation Z come into question as an important issue. Generation Z benefits from digitalization in many ways, including faster and easier access to information, the elimination of time and space constraints in many issues, easier access to various needs such as shopping, education, entertainment and communication, faster completion of work that needs to be done, the ability to perform multiple tasks at the same time and the establishment of a universal perspective. Disadvantages include distraction, screen addiction beginning in childhood, diminished capacity to conduct business using traditional ways, cyber dangers and decreases in personal information security, and future risk to individual security from sharing on social media platforms. All of this highlights the necessity of understanding the benefits and drawbacks of digitalization for Generation Z, called as the Digital Generation.