Noisy chaotic dynamics in commodity markets

The nonlinear testing and modeling of economic and financial time series has increased substantially in recent years, enabling us to better understand market and price behavior, risk and the formation of expectations. Such tests have also been applied to commodity market behavior, providing evidence of heteroskedasticity, chaos, long memory, cyclicity, etc. The present evaluation of futures price behavior confirms that the resulting price movements can be random, suggesting noisy chaotic behavior. Prices could thus follow a mean process that is dynamic chaotic, coupled with a variance that follows a GARCH process. Our conclusion is that models of this type could be constructed to assist in forecasting prices in the short run but not over long run time periods.First version received: June 2001/Final version received: March 2003     

Reasoning under uncertainty and multi-criteria decision making in data privacy

By means of an integration of decision theory and probabilistic models, we explore and develop methods for improving data privacy. Our work encompasses disclosure control tools in statistical databases and privacy requirements prioritization; in particular we propose a Bayesian approach for the on-line auditing in Statistical Databases and Pairwise Comparison Matrices for privacy requirements prioritization. The first approach is illustrated by means of examples in the context of statistical analysis on the census and medical data, where no salary (resp. no medical information), that could be related to a specific employee (resp. patient), must be released; the second approach is illustrated by means of examples, such as an e-voting system and an e-banking service that have to satisfy privacy requirements in addition to functional and security ones. Several fields in the social sciences, economics and engineering will benefit from the advances in this research area: e-voting, e-government, e-commerce, e-banking, e-health, cloud computing and risk management are a few examples of applications for the findings of this research.     

The dimensional assessment of personality in drug addicts: a mixed-effects Rasch model approach

Drug abuse results from a series of different factors, such as social and family issues. Subjects more vulnerable to develop an addiction are, for instance, people living in high-stress environments who may resort to addiction in order to cope with their circumstances, such as demanding jobs, family crisis or other situations or people living in low-income households where violence occurs, who may be triggered into addiction as a way to escape negative emotions or ignore any underlying problems or issues. Psychometric research in the field of drug dependence has focused on identifying certain personality characteristics. It is now generally agreed that personality may influence, precipitate or perpetuate substance abuse. The aim of this paper is to perform a dimensional assessment of personality in a sample of drug addicts. To better understand the complexity of addictive behaviours of substance-using individuals, the Cloninger’s temperament and character inventory test is employed while the item response data analysis is performed by mixed-effects Rasch models. These models combine the advantages both of Rasch measurement framework for latent variables and of models with hierarchical data. To evaluate the differences in dimensions of temperament and character inventory test in subjects with drug addiction, we fit and compare a sequence of mixed-effects Rasch models. Results from models fitting are compared and discussed for a data set of 84 participants.     

Del machismo a la coparentalidad. Evolución de las mentalidades en Italia

En el presente artículo se analizan los complejos procesos legislativos y judiciales necesarios para establecer el derecho de coparentalidad en la reglamentación laboral italiana. Tras identificar en el ordenamiento jurídico la tendencia a equiparar la protección de la familia con el apoyo a la mujer y a la maternidad, se investiga la evolución legislativa que ha llevado a reconocer al padre como pilar fundamental en la crianza de los hijos. Por último, se analiza en detalle la jurisprudencia que, con su interpretación de los principios legislados, ha contribuido a superar la resistencia de la cultura patriarcal al cambio.     

Structuring of temporary multi‐organizations: Contingency theory in the building sector

The appropriate management of construction projects presupposes a clear comprehension of the structure of the temporary multi‐organization (TMO); however, most of the work on the structuring of TMOs has concentrated either on procurement strategies or the structure of individual organizations. Current approaches, therefore, do not fully consider the roles of all project stakeholders, the informal communications, and the complexity of the client organization. Instead, we argue that the contingency theory contributes to the understanding of the structuring of TMOs. The analysis of 27 recent construction projects allows us to identify two contingency factors and patterns of configuration of the TMO.     

Price rigidity and market-clearing: a conceptual clarification

This article tests the view (derived from Hicks and Patinkin)that non-market clearance may be caused by slow adjustment (‘processrigidity’). There are models where market-rationing ispresent and derives from some form of rigidity, but this rigiditycannot be considered as process rigidity. It is similarly possibleto accommodate the idea of process rigidity within the Marshallianresearch programme. What is missing is that market-rationingmight be its corollary. The reason such a causal link is oftenbelieved to exist lies in a generic use of the concept of rigidity,used to designate alternative and incompatible phenomena: ‘exogenousend-state rigidity’ and ‘equilibrium end-state rigidity’,as well as process rigidity. It is true that these first twoforms of rigidity create market rationing. The belief that slowadjustment also generates market rationing results from theunwarranted extension to process rigidity of conclusions whichare only valid for the first two.     

Forecasting interest rates with shifting endpoints

We consider forecasting the term structure of interest rates with the assumption that factors driving the yield curve are stationary around a slowly time‐varying mean or ‘shifting endpoint’. The shifting endpoints are captured using either (i) time series methods (exponential smoothing) or (ii) long‐range survey forecasts of either interest rates or inflation and output growth, or (iii) exponentially smoothed realizations of these macro variables. Allowing for shifting endpoints in yield curve factors provides substantial and significant gains in out‐of‐sample predictive accuracy, relative to stationary and random walk benchmarks. Forecast improvements are largest for long‐maturity interest rates and for long‐horizon forecasts. Copyright © 2013 John Wiley & Sons, Ltd.     

‘Stop Being a Tourist!’ New Dynamics of Urban Tourism in Berlin‐Kreuzberg

Berlin is witnessing a massive tourism boom, and parts of it can be described as ‘new urban tourism’, which shows a preference for off the beaten track areas and ‘authentic’ experiences of the city. This form of tourism seems especially salient in Kreuzberg. It is here that an openly articulated critique of tourism attracted national attention in 2011 and has not ceased to do so since. This article aims to better understand the conflictive potential of (new urban) tourism in Kreuzberg. We argue that the readily expressed negative attitudes against tourists and the easily accepted link between tourism and gentrification have to be explained against the backdrop of certain housing‐market dynamics. Rising rents and a diminution in the number of flats available for rent are fuelling fears of gentrification in Kreuzberg, while the interest shown in new urban tourism and the comparatively low‐priced real‐estate market in Berlin result in a growing number of holiday flats. Although adding only slightly to the tightening of the housing market, holiday flats render complex processes of neighborhood change visible and further sustain an already prevalent tourism critique.     

Productivity Gains and Spillovers from Offshoring

Offshoring is generally believed to be productivity enhancing and this belief is underpinned by economic theory. This paper estimates the impact of materials and business services offshoring on productivity in Belgium over the period 1995–2004. It contributes to the literature: (i) by examining this issue separately for manufacturing and market services industries and (ii) by investigating the possibility of forward and backward spillovers from offshoring, i.e. that productivity gains from offshoring feed through to upstream and downstream industries. Results show that materials offshoring has no effect on productivity, while business services offshoring leads to productivity gains in manufacturing. Furthermore, there is no evidence of either forward or backward spillovers from offshoring.     

On the Welfare Cost of Economic Fluctuations in Developing Countries*

Macroeconomic fluctuations are much stronger in developing countries than in the United States. Yet, while a large literature debates the welfare cost of economic fluctuations in the United States, it remains an open question how large that cost is in developing countries. Using several models, we provide such a measure. We find that the welfare cost of consumption volatility per se is far from trivial and averages a substantial multiple of the corresponding U.S. estimate. Moreover, in many poor countries, the welfare gain from eliminating volatility may in fact exceed the welfare gain from an additional percentage point of growth forever.