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.     

Entrenched Board in New Public Firms： An Empirical Study of Chinese IPOs

This study empirically investigates the impact of managerial entrenchment on firm financial performance of Chinese firms initial public offerings （IPOs）. Using 142 firms listed in the Shenzhen Stock Exchange （SZSE）, which was collected from the Guotaian Research Service Center （GTA-RSC） databases, this study uses two proxies to measure firm performance and three proxies to measure managerial entrenchment. The two proxies for firm performance are Tobins＇ Q and return on assets （ROA）, and the three proxies for managerial entrenchment are entrenchment 1, entrenchment 2, and entrenchment 3. These three entrenchment proxies are derived from the principal component analysis （PCA）. Though previous studies of managerial entrenchment and firm performance variables suffer from endogeneity, with respect to the corporate governance it is unclear as to which variables are endogenous and which are exogenous. This study confirms that the data are linear and no endogeneity issue should be address in this study, but only heteroskedasticity, non-normality for Tobins＇ Q are a problem, therefore, the regression method employed for Tobins＇ Q is the generalised least square （GLS） and the ordinary least square （OLS） between estimators for ROA. The regression result for Tobins＇ Q reveals that managerial entrenchment is negatively impact on firm performance. The results are in contradiction to the stewardship theory for new firms whereas the managerial entrenchment for new firms is positive. Furthermore, only one entrenchment proxy yields a significant coefficient. In conclusion, the negative results of entrenchment proxies were caused by the different institutional structures and legal systems which are the Chinese corporations that are still largely owned and controlled by a state and hence the centralised state controlled was responsible for all managerial actions.     

Where Do Breakthroughs Come From? Characteristics of High‐Potential Inventions

Breakthrough technological inventions create the foundation for many innovative opportunities. Through novel scientific fundamentals and unique combinations of knowledge, they form a new basis for technology development and innovation, shifting their industry's mindset about what is feasible and valuable. Prior research has, to date, characteristically taken an organizational‐level perspective on technology breakthroughs, seeking to explain the occurrence of breakthroughs as a function of firm‐level characteristics and processes. This tells us less, however, about the underlying knowledge structures of the technologies themselves. This research is based on the assumption that an examination of the knowledge foundations of high‐potential inventions can enrich our understanding about the underlying features of innovations that transform industries and advance societies. In this manner, we can clarify how certain technologies are advanced and extended, providing the basis for future discoveries. Our analysis focuses on high‐potential patents: those having the highest number of forward citations in a given class. We conduct this analysis on a sample of 298 breakthrough patents and two comparison nonbreakthrough groups in drug and semiconductor classes. Our results show that breakthrough technologies, compared with nonbreakthroughs, are more likely to build on: (1) the past technological developments of others, by backward citing and embodying knowledge from prior discoveries (earlier patents), but not one's own previous developments; (2) the latest technologies, by backward citing recent patents; (3) geographic proximity, evidenced by the fact that the focal patents backward cite patents from one's own country; and (4) greater technological breadth, evidenced by the fact that knowledge captured in the patents encompasses a larger number of technical fields. Based on these results, we frame the occurrence of breakthroughs as involving a process where these significant developments happen early in the progress of a technology, but after some relevant knowledge has accumulated. This reinforces the concept that a learning effect needs to occur before breakthroughs can happen. In addition, our findings suggest that the knowledge underlying breakthroughs is likely to come from other organizations or individuals, rather than the developing entity. They also incorporate broader insights from technological diversity but do not exhibit geographic diversity. Instead, they are associated with geographic proximity, which may better enable knowledge sharing and integration given the reliance on other entities and diverse knowledge.     

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.     

Can Micro Health Insurance Reduce Poverty? Evidence From Bangladesh

This article examines the impact of micro health insurance on poverty reduction in rural areas of Bangladesh. The research is based on household‐level primary data collected from the operating areas of the Grameen Bank during 2006. A number of outcome measures are considered; these include household income, stability of household income via food sufficiency and ownership of nonland assets, and the probability of being above or below the poverty line. The results show that micro health insurance has a positive association with all of these indicators, and this is statistically significant and quantitatively important for food sufficiency.     

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.