Using Complex Surveys to Estimate the L1‐Median of a Functional Variable: Application to Electricity Load Curves

Mean profiles are widely used as indicators of the electricity consumption habits of customers. Currently, in Électricité De France (EDF), class load profiles are estimated using point‐wise mean profiles. Unfortunately, it is well known that the mean is highly sensitive to the presence of outliers, such as one or more consumers with unusually high‐levels of consumption. In this paper, we propose an alternative to the mean profile: the L ₁ ‐ median profile which is more robust. When dealing with large data sets of functional data (load curves for example), survey sampling approaches are useful for estimating the median profile avoiding storing the whole data. We propose here several sampling strategies and estimators to estimate the median trajectory. A comparison between them is illustrated by means of a test population. We develop a stratification based on the linearized variable which substantially improves the accuracy of the estimator compared to simple random sampling without replacement. We suggest also an improved estimator that takes into account auxiliary information. Some potential areas for future research are also highlighted.     

Part-time work in the public health service of Denmark,France and the UK

The aim of this paper is to consider the extent to which and the ways in which part-time work is used in the health services of Denmark, France and the UK. The reasons for and the implications of introducing part-time work in the three EU countries are also analysed and compared. Data were collected using questionnaires and interviews from hospitals in Denmark, France and the UK. Questionnaires were completed by heads of department and by part-time employees. Interviews (for the UK sample only) were held with the managers responsible for the introduction of flexible working practices. The findings show that part-time employment is the most common flexible working practice in the health services of all three countries but that the purpose of its introduction differs from one country to another. Part-time work seemed to have satisfied the desire of those who run the National Health Service (NHS) in the UK for cost reduction and for flexibility of working practices. In the French health service it was aimed at creating jobs, whereas in Denmark it was a response to increasing employee demand for flexible working. It was also found that, contrary to the Danish case with its established tradition of flexible working and equality in employment, the full-time working traditions and the male-dominated cultures of the health services in France and in the UK have often undermined the importance and benefits of part-time employment.     

Market crises and Basel capital requirements: Could Basel III have been different? Evidence from Portugal,Ireland, Greece and Spain (PIGS)

Basel III represents a crucial step in strengthening the capital rules underlying banking operations, aimed at reducing the probability and severity of a systemic crisis. Alongside two supplementary capital buffers, the Basel Committee of Banking Supervision imposed severe pressure on the Value-at-Risk based Internal Models Approach in order to increase. This is to increase the capital base by adding the stressed Value-at-Risk component in an effort to reduce reliance on internal models while keeping the Standardized Approach avenue open. However, even though those measures might appear theoretically correct, evidence gathered for long and short exposures in Portugal, Italy, Greece and Spain highlights several defects in Basel III. We emphasize that leptokurtic models, primarily those derived from Extreme Value Theory, should be enforced in the regulations given their superior performance in market crises, and that Basel II could have shielded against 2008 mayhem provided that heavy-tailed techniques had been employed.     

Long memory and structural breaks in modeling the return and volatility dynamics of precious metals

We investigate the potential of structural changes and long memory (LM) properties in returns and volatility of the four major precious metal commodities traded on the COMEX markets (gold, silver, platinum and palladium). Broadly speaking, a random variable is said to exhibit long memory behavior if its autocorrelation function is not integrable, while structural changes can induce sudden and significant shifts in the time-series behavior of that variable. The results from implementing several parametric and semiparametric methods indicate strong evidence of long range dependence in the daily conditional return and volatility processes for the precious metals. Moreover, for most of the precious metals considered, this dual long memory is found to be adequately captured by an ARFIMA–FIGARCH model, which also provides better out-of-sample forecast accuracy than several popular volatility models. Finally, evidence shows that conditional volatility of precious metals is better explained by long memory than by structural breaks.     

Perceived international environmental factors and corporate voluntary disclosure practices: An empirical study

Drawing upon the contingency theory of organisations, we identify a set of perceived international environmental factors and examine how these factors influence a company's voluntary disclosure levels. The perceived international environmental factors identified are (a) intensity of global competition, (b) international socio-political institutions, (c) international accounting standards, and (d) international financial institutions. Based on data collected from 100 Egyptian non-financial listed companies, the results of multiple regression analysis indicate that the level of a company's voluntary disclosure is positively and significantly associated with its perceived influence of (a) international socio-political institutions (such as the United Nations, the European Union, the Association of South East Asian Nations, the World Trade Organization, and the Organization for Economic Co-operation and Development), (b) international accounting standards, and (c) international financial institutions (such as the World Bank and the International Monetary Fund). Contrary to our expectations, our findings reveal no significant association between voluntary disclosure level and perceived intensity of global competition. Our study contributes to the international accounting disclosure field by providing evidence from Egypt that perceived international environmental factors may influence the type and level of accounting disclosures by organisations. These findings are also applicable to other emerging countries.     

Characteristics of innovating firms in Tunisia: The essential role of external knowledge sources

This article is dedicated to the analysis of the first innovation survey of the Tunisian firms. Starting from basic mechanisms of innovation processes and existing results on other developing countries, we test a set of assumptions on the characteristics of innovating firms in a developing country like Tunisia. The analysis of product and process innovations shows the essential role played by external technical knowledge sources: firms must be able to benefit at least from one such a source in order to attain a significant innovation propensity. We also show that the profile of Tunisian firms can be contrasted with other developing countries. The main contrast concerns the limited role of internal R&D and the insignificant role played by foreign participation. For both types of innovations, another important contrasting result concerns the role of sectoral membership. In Tunisia, this dimension does not seem to structure enough systematically the innovative capabilities of firms. That could indicate an immaturity of sectoral systems of innovations in this country.     

Risk taking under heterogenous revenue sharing

We examine the impact of informal risk sharing on risk taking incentives when transfers are organized through a social network. A bilateral partial sharing rule satisfies that neighbors share equally a part of their revenue. In such a society, correlated technologies generate interdependent risk levels. We obtain three findings. First, there is a unique and interior Nash-equilibrium risk profile, and it is in general differentiated and related to the Bonacich measure of the risk sharing network. Second, more revenue sharing enhances risk taking on average, although some agents may lower their risk level. Last, we find that under investment might often be observed.     

Islamic Banking in Malaysia: Unchartered Waters

This paper explores the Islamic banking business in Malaysia since its beginning in 1983. The Islamic banking sector has achieved its target of 20% market share in assets and deposits in 2010. To boost the industry's competitiveness and efficiency, the demands of the market forces will have to be delicately balanced with the dictates of the Shari'ah. The search for niche Islamic banking products warrants enhancements in the current regulatory, legal, and fiscal infrastructure for Islamic banking, without which these products cannot be a viable alternative to the conventional ones. While the prevailing infrastructure is conducive to Islamic banking products that hold similar characteristics with interest‐bearing loans, Shari'ah compliance can be a futile exercise when the purpose of the law (maqasid al‐shari'ah) is overlooked, for there is much more to Islamic banking than the elimination of interest.     

迪拜推迟偿债得不偿失

【摩根士丹利11月30日】11月25日，迪拜政府发布了两项重大声明，对投资者情绪产生了截然相反的影响。首先是好消息：迪拜政府发行的50亿美元债务获得了阿布扎比政府控股的两家银行的全额认购。迪拜官方称，这是其200亿美元债券发行计划的一部分。