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).     

Choosing sides in the trilemma: international financial cycles and structural change in developing economies

ABSTRACT

This paper analyzes the impact of international financial cycles on structural change in developing economies. It is argued that the impact of these cycles depends on the specific combination of macroeconomic and industrial policies adopted by the developing economy. The cases of Brazil and Argentina are contrasted with those of Korea and China. In the Asian economies, macroeconomic policy has been a complementary tool along with industrial policy to foster the diversification of production and capabilities. Inversely, in the case of the Latin American countries, long periods of real exchange rate (RER) appreciation, combined with the weaknesses (or absence) of industrial policies, contributed to the loss of capabilities and lagging behind.     

Task‐based structures in open source software: revisiting the onion model

Studies on Open Source Software (OSS) developer communities have long stated that there is a relationship between community structure and tasks carried out by project members. This relationship has been exemplified by the onion model, which has been instrumental in understanding self‐coordination in OSS projects. Despite its ubiquity, there is a lack of empirical evidence to validate the relative position of each task cluster within the onion model. In this study, we map out the community structure of a large open source project and observe its bug‐fixing patterns to explore the relationship between tasks and structure. Our study makes three significant contributions. First, we find no empirical evidence to support the structural location of bug‐fixing tasks in the onion structure. Second, we find empirical evidence to support the core‐periphery continuum model linking an actor’s coreness to problem‐solving ability. Third, our results suggest that the importance and location of each task within the core‐periphery structure evolve over time. These findings add clarity to the community structure and their implications for the management and coordination of collaborative innovation projects.     

The demand for and the supply of distribution services: A basis for the analysis of customer satisfaction in retailing

This paper brings together two bodies of literature. One of them is a literature on the special role of the consumer in retailing. The other one is the literature on customer satisfaction. This joining of literatures is accomplished by identifying distribution services as outputs of retail firms and fixed inputs into the production functions of consumers and relaxing the standard assumption that the demand for these services is always equal to the supply of these services. The result is a new conceptual framework for the analysis of customer satisfaction in retailing. This framework extends the basic ideas on customer satisfaction developed for manufacturing in a homogeneous single product setting to the heterogeneous multi-product setting relevant for many retailers. The paper illustrates one approach to the implementation of this framework with data for a set of supermarkets in Pamplona, Spain, that measure distribution services by asking consumers questions explicitly identifying these services. The five main categories of distribution services identified by the conceptual framework and measured in the data are economically important and statistically robust determinants of customer satisfaction with supermarkets. These results are obtained controlling for other variables typical of the customer satisfaction literature and measuring customer satisfaction in a manner consistent with that literature. The results are robust to corrections for sample selection and alternative estimation methods. Perhaps our most interesting novel result is that the effect of the determinants of customer satisfaction on future purchase intentions in the supermarket case is different when measured directly in a one stage process than when measured indirectly in a two stage process through the attributes/satisfaction/ purchase intentions chain.

The exchange rate cycle in Argentina

This article discusses the secular volatility of output, inflation, the exchange rate, and poverty in Argentina. Inflation, currency devaluation and a wide gross domestic product (GDP) cycle have been recurrent problems in Argentina for several decades. The literature has extensively discussed those issues from different viewpoints. This study focuses on a relatively unexplored theme that may contribute to a partial explanation. It deals with the continuous tendency to equalize different profitabilities resulting, in turn, from remarkably different sectoral purchasing power parities. Thus, for any given exchange rate, an incessant tendency toward the equalization of profitabilities generates opposing inflationary and devaluatory pressures. The resulting inflation-devaluation cycle feeds income redistribution, GDP fluctuation, real exchange rate instability, and high levels of uncertainty.     

Trends in time allocation: A cross-country analysis

Using detailed time-use data for seven industrialized countries from the 1970s until today we document general decreases in men's market work coupled with increases in men's unpaid work and child care, and increases in women's paid work and child care coupled with decreases in unpaid work. We also find almost universal increases in the time devoted to watching television over this period, and uncover a widespread increase in leisure inequality in favor of lower educated adults. Trends in leisure inequality mirror the general increase in income and earnings inequality experienced in most countries over this period, especially after the mid-1980s. All these findings are consistent with previous results for the US. However, in contrast to the increases in leisure found for the US, we fail to find common trends in leisure time across countries over the period analyzed.     

Building internal business scenarios based on real data from a performance measurement system

This paper presents a new methodology to build internal business scenarios from the data gathered by some key performance indicators (KPIs) defined within a performance measurement system. The application of the principal components analysis technique leads to the identification of latent relationships between KPIs that underlies some important business aspects. Further, this methodology allows to represent not only the temporal evolution of the organisation as a function of these business aspects but also the definition and determination of internal business scenarios, being therefore the source of meaningful managerial information. At the end of the paper, results of a practical application are presented and discussed, as well as their importance for the organisation from a decision making point of view.