The Surge in Short-Duration Contracts in Spain

Until the outbreak of the recent economic and financial crisis, Spain was leading the ranking of countries with the largest share of temporary employees. During the crisis this share has fallen to its lowest level in decades, but this does not mean that working conditions in Spain have improved. The flow of new temporary contracts is larger than ever before. A particularly striking feature is the steep growth in the volume of fixed-duration contracts lasting less than a week or a month. We document these trends and analyse how this phenomenon has affected the transition from temporary to permanent employment.     

Extending multi-tenant architectures: a database model for a multi-target support in SaaS applications

Multi-tenant architectures (MTAs) are considered a cornerstone in the success of Software as a Service as a new application distribution formula. Multi-tenancy allows multiple customers (i.e. tenants) to be consolidated into the same operational system. This way, tenants run and share the same application instance as well as costs, which are significantly reduced. Functional needs vary from one tenant to another; either companies from different sectors run different types of applications or, although deploying the same functionality, they do differ in the extent of their complexity. In any case, MTA leaves one major concern regarding the companies’ data, their privacy and security, which requires special attention to the data layer. In this article, we propose an extended data model that enhances traditional MTAs in respect of this concern. This extension – called multi-target – allows MT applications to host, manage and serve multiple functionalities within the same multi-tenant (MT) environment. The practical deployment of this approach will allow SaaS vendors to target multiple markets or address different levels of functional complexity and yet commercialise just one single MT application. The applicability of the approach is demonstrated via a case study of a real multi-tenancy multi-target (MT²) implementation, called Globalgest.     

Incidence,effects, dynamics and routes out of overqualification in Europe: a comprehensive analysis distinguishing by employment status

This study aims to improve our understanding of overqualification by incorporating distinctions in employment status (i.e. self-employed workers, private employees and public employees) in the analysis of the incidence, effects, dynamics and routes out of overqualification. To this end, we apply discrete choice – ordered and nonordered – and count models to the data obtained from the European Community Household Panel for the EU-15. Our results indicate that the incidence of overqualification varies by employment status, where self-employed workers report the lowest occurrence. Furthermore, this analysis suggests that overqualification is a permanent phenomenon and demonstrates that successful pathways out of overqualification differ by employment status. The implications of these results for education and labour market policies are also discussed.     

Natural resources and international labour mobility

We study the relationship between natural resource wealth and (skilled and unskilled) emigration. The source data for international migration rates come from Brücker, Capuano, and Marfouk (2013) and measures of resource wealth from the World Bank database. We find that natural resource abundance reduces skilled emigration regardless of countries’ natural wealth, but that natural resources reduce unskilled emigration only in resource-rich countries.     

Identifying the Transition from Efficient-Market to Herding Behavior: Using a Method from Econophysics

We test whether “detrended fluctuation analysis” (DFA)—an econophysics method—identifies the transition from efficient-market trading to herding behavior and the rise of the NASDAQ dot.com stock market bubble. DFA divides a time series into “segments” of varying lengths and then tests whether power-law distributions exist within the segments. A power-law distribution of stock-price changes within a segment indicates herding behavior and the start of the dot.com bubble. The clarity of the transition indication depends on both segment lengths and segment starting dates. Our findings show that DFA can be used to identify the beginning of stock-market bubbles but not the beginning of crashes.     

Short-term asymptotics for the implied volatility skew under a stochastic volatility model with Lévy jumps

The implied volatility skew has received relatively little attention in the literature on short-term asymptotics for financial models with jumps, despite its importance in model selection and calibration. We rectify this by providing high order asymptotic expansions for the at-the-money implied volatility skew, under a rich class of stochastic volatility models with independent stable-like jumps of infinite variation. The case of a pure-jump stable-like Lévy model is also considered under the minimal possible conditions for the resulting expansion to be well defined. Unlike recent results for “near-the-money” option prices and implied volatility, the results herein aid in understanding how the implied volatility smile near expiry is affected by important features of the continuous component, such as the leverage and vol-of-vol parameters. As intermediary results, we obtain high order expansions for at-the-money digital call option prices, which furthermore allow us to infer analogous results for the delta of at-the-money options. Simulation results indicate that our asymptotic expansions give good fits for options with maturities up to one month, underpinning their relevance in practical applications, and an analysis of the implied volatility skew in recent S&P 500 options data shows it to be consistent with the infinite variation jump component of our models.     

Determinants of knowledge-based entrepreneurship: an exploratory approach

We intend to further the research related to the factors that determine successful entrepreneurial endeavours by academic researchers, and thus put forth an exploratory model of Knowledge-Based Entrepreneurship (KBE). Given the lack of extant adequate indicators, a new scale was developed based on the most frequently cited constructs in the literature. A sample of 1,401 researchers from Portuguese universities was administered a questionnaire and the data collected permitted a validation with regards to the psychometric properties of the questionnaire, to see its applicability to the study. The findings suggest that the absence of a patenting history or start-up portfolio act as significant barriers to academic entrepreneurship. However, when the institutional strategy is to increase patenting and spin-off activities, the university should begin investing in creating a networking environment capable of reinforcing the researchers’ Social Capital. Observing the example of successful entrepreneurs motivates other researchers to consider the possibility of developing their own ventures. The Structural Equations Modelling (SEM) approach allowed for us to identify and measure the non-linear relationships that shape the core of KBE and influence the attainment of measurable outcomes aimed at encouraging entrepreneurship. A relatively high share of the variance of the dependent variables is explained by the model, ensuring their representativeness and contributing to the state-of-art of the knowledge in this research field.     

OCB and external–internal social networks: effects on individual performance and adaptation to change

In this study, we develop and test a model that links one's internal and external social network structures to his or her willingness and ability to adapt in a changing work context. Using a survey data from 371 employees working in 133 different branches of a large financial firm, we find that individual behaviors that explain task performance and individual adaptation to change are affected by a number of supportive social ties (size of the support network) with which one receives support inside and, mostly, outside the workplace. The results also show that individual performance and adaptation to change are affected by the level of workers' organizational citizenship behavior. We also identify a mediating effect exerted by the informational network structure (mostly an internal network) on the relationship between the support network (mostly an external network) and individual task performance.     

The introduction of seasonal unit roots and cointegration to test index aggregation optimality: An application to a Spanish farm price index

In this paper we present a methodological proposal of the way integration and cointegration analysis can best be used to test if the level of aggregation of an index is adequate. Using this proposal, we enquire the extent to which a Spanish aggregate farm price index captures the behavior of its components. First version received: October 1994/final version received: September 1998     

The insolvent subsidiary and liability of the parent corporation in the USA,Argentina, and UNCITRAL

The increasing unacceptability of the concept of entity law and the emergence of the doctrine of enterprise law with respect to many aspects of the legal relationships of parent and subsidiary corporations particularly in insolvent situations is a very interesting issue. This change is very significant because it reflects a growing unwillingness on the part of the courts and legislatures to continue accepting the traditional view of corporate law when it no longer corresponds to the economic reality of the modern business enterprise in a complex industrialized international society. This paper examines the American case law and in particular the decisions that have imposed liability where a company is liable for the obligations of an insolvent subsidiary and by contrast the decisions that have denied liability. The paper also examines the position in Argentina within the Argentine law and the UNCITRAL recommendations in respect of liability issues within corporate groups in insolvency. Copyright © 2010 John Wiley & Sons, Ltd.