Stochastic Models of Implied Volatility Surfaces

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).     

Towards a Theory of Organizational Improvisation: Looking Beyond the Jazz Metaphor

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.     

Rituals of cruise consumption and the 'new' middle class: desiring and 'devouring' maritime cruises

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.     

Perceptions of poverty attributions in Europe: a multilevel mixture model approach

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.     

A PRIMER ON GLOBAL GAMES APPLIED TO MACROECONOMICS AND FINANCE

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.     

Contracting in a Market with Differential Information

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.

     

Effort Elicitation,Wage Differentials and Income Distribution in A Wage‐Led Growth Regime

Motivated by the empirical evidence on endogenous labor effort and wage differentials, this paper explores implications for distribution and growth of firms using different strategies to elicit effort from workers. The frequency distribution of effort‐elicitation strategies across firms is governed by a replicator dynamic that generates wage differential as a long‐run equilibrium. Although firms willing to elicit more effort have to compensate workers with a higher wage rate, a larger proportion of firms adopting such strategy will not necessarily produce a higher wage share and thereby a higher growth rate. The intuition is that, depending on the accompanying rise in labor productivity, the wage share may not vary positively with the proportion of firms paying higher wages.     

Capital services estimates in Portuguese industries, 1977–2003

This paper presents capital services estimates for 26 Portuguese industries for the 1977–2003 period. The estimation procedure follows an integrated approach under which the flows of capital services are approximated as a proportion of the capital stock converted into standard efficiency units. Our findings suggest a close proximity between the evolution of capital flows and the observed fluctuations of Portuguese macroeconomic growth. TFP growth estimates based on growth accounting reveal, furthermore, a very disappointing performance of the Portuguese economy during the period under study, with an average annual rate of TFP growth of 0.8% being observed. Performance varies across industries, but the bulk of activities show very modest rates of TFP growth.     

媒体情绪与房价波动*

本文使用2000—2015年中国112个大中城市媒体报道和房价月度指数研究了媒体异质性对房价波动的影响。研究发现,纸媒情绪对房价波动的影响大于网媒情绪,中央媒体情绪对房价波动的影响大于地方媒体情绪,明星微博情绪对房价波动的影响大于普通微博情绪,媒体语气确定性和报道篇幅对房价波动有正影响,明星城市媒体情绪较非明星城市更易引起房价波动。据此,为防范非理性房价波动,应加强对不同媒体报道的监管。     

Where to vacation? An agent-based approach to modelling tourist decision-making process

Agent-based models (ABMs) are becoming more relevant in social simulation due to the potential to model complex phenomena that emerge from individual interactions. In tourism research, complexity is a subject of growing interest and researchers start to analyse the tourism system as a complex phenomenon. However, there is little application of ABMs as a tool to explore and predict tourism patterns. The purpose of the paper is to develop an ABM that increases knowledge in tourism research by (i) considering the complexity of tourism phenomenon, (ii) providing tools to explore the complex relations between system components and (iii) giving insights on the functioning of the system and the tourist decision-making process. A theoretical ABM is developed to improve knowledge on tourist decision-making in the selection of a destination to vacation. Tourists’ behaviour, such as individual motivation, and social network influence in the vacation decision-making process are hereby discussed.