We propose a market–based approach to the modelling of implied volatility, in which the implied volatility surface is directly used as the state variable to describe the joint evolution of market prices of options and their underlying asset. We model the evolution of an implied volatility surface by representing it as a randomly fluctuating surface driven by a finite number of orthogonal random factors. Our approach is based on a Karhunen–Loeve decomposition of the daily variations of implied volatilities obtained from market data on SP500 and DAX options. We illustrate how this approach extends and improves the accuracy of the well–known 'sticky moneyness' rule used by option traders for updating implied volatilities. Our approach gives a justification for the use of 'Vegas' for measuring volatility risk and provides a decomposition of volatility risk as a sum of independent contributions from empirically identifiable factors. (J.E.L.: G130, C14, C31). 相似文献
This study investigates organizational diversity discourses in Turkey – a non-Western, politically relevant, yet underrepresented context. Using a Foucauldian perspective on power and discourse, we scrutinize how power relations in the Turkish context are (re)produced. Based on our analysis of company websites and semi-structured interviews with various actors (e.g., HR managers), we propose a conceptual framework of the discursive construction of diversity subjects at work along the dimensions of (1) visibility of organizational diversity discourses and (2) contestation of meaning within organizational diversity discourses. The combination of these dimensions yields four discursive dynamics as illustrated in our data (Advertising, Avoiding, Disrupting, Tabooing). This framework may inspire future context- and power-sensitive investigations on diversity discourses at the workplace. 相似文献
abstract This paper calls for research on organizational improvisation to go beyond the currently dominant jazz metaphor in theory development. We recognize the important contribution that jazz improvisation has made and will no doubt continue to make in understanding the nature and complexity of organizational improvisation. This article therefore presents some key lessons from the jazz metaphor and then proceeds to identify the possible dangers of building scientific inquiry upon a single metaphor. We then present three alternative models – Indian music, music therapy and role theory. We explore their nature and seek to identify ways in which the insights they generate complement those from jazz. This leads us to a better understanding of the challenges of building a theory of organizational improvisation. 相似文献
This paper assesses the current status and future prospects for bioregional planning in the Southern Appalachian Man and the Biosphere (SAMAB) region in the United States. The SAMAB region is one of the most biodiverse temperate regions in the world. The region's environment is threatened by development, air and water pollution, and invasive species. Numerous institutions in the region have some responsibility for protecting the region's environment, including the National Park Service, the US Forest Service, the US Environmental Protection Agency, the US Fish and Wildlife Service, several states, hundreds of municipalities, and numerous active non-profit organizations. Twenty-seven people associated with bioregional planning were interviewed to gauge their opinions on the state of bioregional planning in the SAMAB region. Overall, the respondents do not believe that the totality of all those efforts comprises bioregional planning because the efforts are limited in scale and scope and somewhat uncoordinated. With respect to the future of the region, the respondents found it difficult to imagine the state of the region 50 and especially 200 years into the future. Additionally, almost all of their definitions of bioregional planning included a spatial dimension but none included a time dimension. Thus, one of our conclusions is that the future of bioregional planning in the region will be hampered by difficulties people responsible for environmental protection have in dealing with ‘the future’. Much effort needs to be expended to inculcate people in the region with the desire to anticipate problems long before they occur. Reactive responses, which characterize the majority of current efforts, are likely to be ‘too little, too late’. 相似文献
The consumption of maritime cruises is one of the most striking facets of the phenomenon of a new middle class emergence in Brazil. This study investigates the use of maritime cruises by emerging middle-class consumers to enact their new social status. Specifically, the research looks at ritualistic behaviour performed by consumers before, during, and after a cruise. The research uses a multi-method design characterised by a combination of ethnography and group discussions. The study contributes to enlarge McCracken’s typology of consumption rituals, showing how emerging consumers use the cruise as a rite of passage, during which they perform rituals of preparation, production, possession, and divestment. It also sheds light on specific rituals performed by consumers in order to transfer meanings from the cruise to their own selves. Finally, the findings suggest that consumption rituals in the context of social ascent may not have the transformative power of traditional rites. 相似文献
The perception of the causes of poverty has long been recognized as a very important factor in the broader study of this social phenomenon. This study covers 15 European Union countries and considers three types of poverty attributions: individualistic, societal, and fatalistic. The individualistic view perception believes the poor are responsible for their situation, the societal perspective blames society for poverty and the fatalistic view considers poverty to be the result of bad luck or fate. A multilevel mixture model with three clusters of countries and six clusters of individuals was identified. Despite the generalization of the social explanations of poverty at the individual or micro level, there are also groups that emphasize more individualistic explanations, blaming the poor for their condition. At the country or macro level, the most developed cluster believes in the individualistic and fatalistic causes of poverty, whereas the least developed clusters explain poverty based on the injustices of society. There is diversity in the way these countries perceive poverty. 相似文献
Providing consumers with unique experiences and immersing them in original contexts are the goals of web entrepreneurs. Researchers and web entrepreneurs have expressed a particular interest in the online customer experience, agreeing on its importance in creating satisfaction, revisiting intention, e-trust and e-loyalty. This paper explores customer experience in the online retail context. The online customer experience is central in forming customers’ perceptions of expectations of online retailers because this experience is highly personal. However, empirical research on the online customer experience remains scarce. The objectives of this unique study are twofold. The first is to compare the effect of online customer experience on the responses of Romanian and Tunisian customers. The comparative analysis is based on two dimensions of the online customer experience assessment tool. These dimensions are cognitive experiential state (flow) and affective experiential state. The second objective is to examine the contribution of each of these two dimensions in explaining overall perceived value, e-satisfaction, e-trust and repurchase intention in the online context, as well as their effects on web entrepreneurial initiatives. The findings reveal the impact of cultural influences on the constructs embedded in the research framework. The implications for practice relate to the increasing importance of online customer experience in tailoring online marketing campaigns. The implications for web entrepreneurship are clearly emphasised by the pathways from online customer experience to entrepreneurial initiatives. These pathways capture the value of customer-generated content in designing innovative business models.
This paper shows how to solve global games applied to macroeconomics and finance. We ascertain the roles of public and private information for the determination of a unique equilibrium, and discuss the informative role of market prices. We examine the impact of public information on social welfare, comparing models with and without complementarities at the aggregate level. 相似文献
This study investigates the potential impact of climate change and armed conflict on inequality in Sub-Saharan Africa (SSA). The system-GMM for a panel of 35 SSA countries is employed using annual data from 1997 to 2018. The empirical results indicate that armed conflict and climate are major drivers of inequality in SSA. The direct impact of the two determinants is more than the indirect impact. Also, the impact of armed conflict is more than the climate change. The coefficients of population growth, output growth, unemployment, natural rent, exchange rate and inflation rate are significant positive predictors of inequality in the SSA. The study advocates for a multidisciplinary inclusive growth strategy that prioritises the climate change reversal, de-escalation of armed conflict, population control, reduction of the unemployment rate and increasing informal sector productivity, to promote inclusive growth and reduce inequality. However, sequencing the policy targets relative to the magnitude of their impact on inequality is extremely crucial. 相似文献
Today’s technology allows firms to collect, store and use different types of data. This has prompted a wide discussion on the effects of access to data on competition and consumer welfare. This discussion has also been present in the energy sector in which advanced technology has allowed for the collection of detailed energy consumption data. Prompted by this discussion on the energy sector, this paper studies an industry where two firms have access to the same technology and compete in prices, but one of them has access to better information about customers. The better informed firm obtains a customer contact advantage, whereas the uninformed firm can still offer a menu of prices without being able to pre-identify the customers. We show that the better informed firm is able to exclude the uninformed firm from the market. This result provides policy insights on the usefulness of considering data access models that can ensure non-discriminatory behaviour.