SEMIPARAMETRIC VECTOR MEM

Financial time series are often non‐negative‐valued (volumes, trades, durations, realized volatility, daily range) and exhibit clustering. When joint dynamics is of interest, the vector multiplicative error model (vMEM; the element‐by‐element product of a vector of conditionally autoregressive scale factors and a multivariate i.i.d. innovation process) is a suitable strategy. Its parameters can be estimated by generalized method of moments, bypassing the problem of specifying a multivariate distribution for the errors. Simulated results show the gains in efficiency relative to an equation‐by‐equation approach. A vMEM on several measures of volatility justifies a joint approach revealing full interdependence. Copyright © 2012 John Wiley & Sons, Ltd.     

Modelling the spatiotemporal distribution of the incidence of resident foreign population

Many European countries have recently experienced a substantial increase in the proportion of immigrants in their populations. The incidence of resident foreigners calculated at a national level does not provide information on the local spatial and temporal distribution of the phenomenon. This information may be of crucial importance for planning local policies. In this article, we suggest a tool for practitioners to provide spatiotemporal maps representing the local distribution of the incidence of resident foreigners in the territory, and changes in spatial trends over time. We illustrate this with Italian data at a municipal level, for the period 2003–2008. To account for spatiotemporal interactions in the data, we propose using a generalized additive model incorporating a smoother of the time and space dimensions. Specifically, we set up a tensor product smoother combining a cubic regression spline basis for time and a soap film spline basis for space. This approach provides a consistent framework to produce spatiotemporal maps which could be effectively used by policy makers to decide the allocation of economic resources at a local level.     

A virtual voyage through 3D structures generated by chaotic mixing of magmas and numerical simulations: a new approach for understanding spatial and temporal complexity of magma dynamics

In this contribution, we present a virtual voyage through 3D structures generated by chaotic mixing of magmas and numerical simulations with the aim to highlight the power of 3D representations in the understanding of this geological phenomenon. In particular, samples of mixed juveniles from Salina island (Southern Italy) are reconstructed in 3D by serial lapping and digital montage and numerical simulations are performed by using a 3D chaotic dynamical system. Natural and simulated magma mixing structures are visualized by using several multimedia tools including animations and “virtual reality” models. It is shown that magma interaction processes can generate large spatial and temporal compositional heterogeneities in magmatic systems. The same topological structures are observed in both 3D reconstructed rock samples and chaotic numerical simulations, indicating that the mixing of magmas is governed by chaotic dynamics. The use of 3D multimedia models gives the opportunity to penetrate into magma mixing structures and to understand their significance in the context of magma dynamics. Such an approach is very powerful since multimedia tools can strongly capture the attention of the reader bringing him/her into an interactive and memorable geological experience.     

Shrinkage estimation of semiparametric multiplicative error models

Within models for nonnegative time series, it is common to encounter deterministic components (trends, seasonalities) which can be specified in a flexible form. This work proposes the use of shrinkage type estimation for the parameters of such components. The amount of smoothing to be imposed on the estimates can be chosen using different methodologies: Cross-Validation for dependent data or the recently proposed Focused Information Criterion. We illustrate such a methodology using a semiparametric autoregressive conditional duration model that decomposes the conditional expectations of durations into their dynamic (parametric) and diurnal (flexible) components. We use a shrinkage estimator that jointly estimates the parameters of the two components and controls the smoothness of the estimated flexible component. The results show that, from the forecasting perspective, an appropriate shrinkage strategy can significantly improve on the baseline maximum likelihood estimation.     

Buy Local! Familiarity and Preferences for Extra Virgin Olive Oil of Italian Consumers

Over the last few years, the origin of the local product has played a central role in consumer choices. This study explores what Italian consumers want and look for when purchasing olive oil by combining a web-based survey and a perceived analysis technique. In particular, preferences for different olive oil attributes as well as the psychographic traits of respondents were revealed through a web-based questionnaire administered to Italian consumers (N = 179). From this questionnaire, respondents who indicated their availability to participate further underwent a preference test under blind conditions (N = 99). Respondents also did an expectation test based on the visual observation of the labels. Results showed that the majority of consumers considered local production, PDO and region as factors of highest importance in determining olive oil quality.     

Linking learning with governance in networks and clusters: key issues for analysis and policy

In this paper we analyse the relationship between governance and learning in clusters and networks. In particular, we see these two key elements as interdependent, suggesting that, under particular circumstances, such interdependence may drive clusters and networks towards a dynamic development trajectory. A pure ‘governance perspective’ makes the development of any locality dependent on the system of powers which exists within the locality or across the global value chain. In parallel, a pure ‘competence-based approach’ focuses mainly on the capabilities of actors to learn and undertake activities. In contrast, we open the prospects for an interdependent relation that may change the actual competences of actors as well as the governance settings and dynamics in networks and clusters. When supported by public policies, the learning process may have the potential to modify the governance environment. Simultaneously, the learning process is intrinsically influenced by economic power, which may seriously affect the development prospects of clusters and networks. This is why an intertwined consideration of both aspects is necessary to promote specific approaches to learning and to design appropriate policies. In this paper we offer two preliminary case studies to clarify some of these dynamics: the first taken from the computers cluster in Costa Rica and the second from an Italian bio-pharmaceutical firm and its production network. The first case study refers to the software cluster that was created from scratch in Costa Rica thanks to an enlightened government policy in coordination with new local enterprises and an important foreign direct investor; while the second reflects on the ability of an individual company to create a network of relationships with large transnational companies in order to acquire new competences without falling into a subordinate position with respect to its larger partners.     

The Governance of Networks and Economic Power: The Nature and Impact of Subcontracting Relationships

Abstract.  Current debate on networking focuses on network structures and firm strategies. In this perspective, theoretical analysis has been concerned with allocative issues. This essay proposes a different interpretation. Starting from the existing theoretical framework, we emphasise the nature and the implications of different types of networks with respect to socio‐economic development from a distributional point of view. Within this context, we develop the analysis of subcontracting starting from the concept of economic power. We then provide an analysis of governance in production by considering the attitudes and the nature of the actors involved. The externalisation of activities by large transnationals, which characterises current corporate restructuring, is often related to the search for greater flexibility, but also for greater power over governments, labour, and subcontractors. Differently, networks based on the mutual dependence of actors, which are not necessarily built around a large firm, could – under particular conditions – reach large production scales or more complex scopes without breaking the links with territorial systems, thus including local objectives in the strategic decision‐making process. Our conclusion is that the impact of subcontracting networks varies enormously. This is crucial to an understanding of future trends and possibilities. Not least, firms and public policy agencies need to understand the implications of different forms of subcontracting network and how those forms actually differ in practice.     

Manipulation of profits in Italian publicly-funded healthcare trusts

ABSTRACT

This paper examines earnings management in state-funded Italian healthcare trusts. Italy is unique in requiring trusts to have balanced budgets by law. Small negative and positive deviations from a balanced budget had quite different consequences. The authors found no evidence of accounting manipulation when trusts posted small losses. However, trusts were found to manipulate discretionary accruals, provisions and non-operating expenses to reduce small positive deviations from zero-profit.