Uncovering Some Causal Relationships Between Productivity Growth and the Structure of Economic Fluctuations: A Tentative Survey

This paper reviews the recent literature on the interactions between business cycles and growth. It focuses on the causality from cycles to growth, but also deals to some extent with the reverse causality. It discusses both “Keynesian” and “Schumpeterian” theories of cycles and growth.     

Schumpeterian Growth Theory and the Dynamics of Income Inequality

In this lecture, it is argued that Schumpeterian Growth Theory, in which growth is driven by a sequence of quality‐improving innovations, can shed light on two important puzzles raised by the recent evolution of wage inequality in developed economies. The first puzzle concerns wage inequality between educational groups, which has substantially risen in the US and the UK during the past two decades following a sharp increase in the supply of educated labor. The second puzzle concerns wage inequality within educational groups, which accounts for a large fraction of the observed increase in wage inequality, although in contrast to between‐group wage inequality it has mainly affected the temporary component of income.     

Improving extreme quantile estimation via a folding procedure

In many applications (geosciences, insurance, etc.), the peaks-over-thresholds (POT) approach is one of the most widely used methodology for extreme quantile inference. It mainly consists of approximating the distribution of exceedances above a high threshold by a generalized Pareto distribution (GPD). The number of exceedances which is used in the POT inference is often quite small and this leads typically to a high volatility of the estimates. Inspired by perfect sampling techniques used in simulation studies, we define a folding procedure that connects the lower and upper parts of a distribution. A new extreme quantile estimator motivated by this theoretical folding scheme is proposed and studied. Although the asymptotic behaviour of our new estimate is the same as the classical (non-folded) one, our folding procedure reduces significantly the mean squared error of the extreme quantile estimates for small and moderate samples. This is illustrated in the simulation study. We also apply our method to an insurance dataset.     

Intra-rater reliability of hip abductor isometric strength testing in a standing position in older fallers and non-fallers

Background

Reduced hip muscle strength has been shown to be a major factor related to falls in older persons. However, comprehensive assessment of hip abduction strength in the clinical setting is challenging. The aim of this study was to investigate the feasibility and intra-rater reliability of a quick and simple hip abductor strength test in a functional standing position.

Methods

Individuals over 65 years of age were recruited from the geriatric department of a university hospital and an outpatient clinic. Thirty-two older subjects, including 16 fallers (≥1 fall during the last 12 months) and 16 non-fallers were included. Maximum voluntary isometric strength (MVIS) and rate of force generation (RFG) of the hip abductors of the right leg were evaluated in a standing position using a hand-held dynamometer. Two test-sessions were carried out. All hip strength values were normalized to participants’ weight. Reliability was determined using the intra-class correlation coefficient agreement (ICC_agreement), the standard error of measurement (SEM) and a Bland and Altman analysis (BA).

Results

All participants completed the strength tests, which took a mean 2.47?±?0.49 min (one limb). Intra-rater reliability was higher for MVIS (0.98_{[0.95–0.99]}) than RFG (ICC?=?0.93_{[0.87–0.97]}) for the entire sample. In the non-fallers, ICC was 0.98_{[0.95–1.00]} (SEM?=?0.08 N.kg^??1) for MVIS and 0.88_{[0.75–0.96]} for RFG (SEM?=?1.34 N.kg^-1.s^-1). In the fallers, ICC was 0.94_{[0.89–0.98]} (SEM?=?0.11 N.kg^??1) for MVIS and 0.93_{[0.84–0.98]} (SEM?=?1.12 N.kg^??1.s^??1) for RFG. The BA plot showed that the MVIS and RFG values did not differ across test-sessions, showing that no learning effect occurred (no systematic effect). The mean differences between test-sessions were larger and the LOA smaller in the fallers than in the non-fallers.

Conclusion

Assessment of hip strength in a standing position is feasible, rapid and reliable. We therefore recommend this position for clinical practice. Future studies should investigate the diagnostic value of hip abductor strength in standing to discriminate between fallers and non-fallers, and to determine if change in strength following a falls prevention program reduces the risk of falls.

     

Who is right about the modern economy: Polanyi,Zelizer, or both?

Zelizer’s work may be read as an attack on the central Polanyian thesis: that the market system threatens social life by the undue prominence it lends the economy in the organization of modern society. The recent publication of Viviana Zelizer’s The Purchase of Intimacy (2005a) is therefore an excellent opportunity to review the general trend of her work Zelizer 1979, 1985, 1994, and contrast her leading ideas to the central thesis that gives Polanyi’s work its particular flavor: the danger encapsulated in the use of modern money and the functioning of the market system. A draft of this essay was presented in March 2007 at a workshop held at the University of London, and a preliminary French version has appeared in a special issue of the Revue du Mauss devoted to Polanyi’s thought (Vol. 29, June 2007). The present version is directed to Zelizer’s views on the relation between market and society. I thank Franck Cochoy, Keith Hart, José Ossandon, and Viviana Zelizer for their helpful comments and advices.

---

Work,Refuge, Transit: An Emerging Pattern of Irregular Immigration South and East of the Mediterranean

Southern and Eastern Mediterranean (SEM) countries have recently turned into receivers of migrants, but they have neither the institutions nor the policies that would allow them to integrate migrants. Therefore, most migrants in SEM countries found themselves in irregular situation. Using a variety of statistical sources, official and non‐official, the article establishes that out of 5.6 million immigrants living in SEM countries in the mid‐2000s, a minimum of 3.6 would be in irregular situation. They belong to three categories: approximately 2 million migrant workers attracted by SEM labour markets where they are employed in the informal sector with no work permit, 1.5 million de facto refugees who cannot obtain the status of refugee and are waiting for resettlement in a third country or return to their homes, and less than 200,000 transit migrants initially bound for Europe, which they are unable to reach for lack of visa. While their reasons to be stranded in the SEM differ, these three categories share the same vulnerable conditions, with no legal access to work, services, or protection.     

Pharmacokinetic parameters estimation using adaptive Bayesian P-splines models

In preclinical and clinical experiments, pharmacokinetic (PK) studies are designed to analyse the evolution of drug concentration in plasma over time i.e. the PK profile. Some PK parameters are estimated in order to summarize the complete drug's kinetic profile: area under the curve (AUC), maximal concentration (C(max)), time at which the maximal concentration occurs (t(max)) and half-life time (t(1/2)).Several methods have been proposed to estimate these PK parameters. A first method relies on interpolating between observed concentrations. The interpolation method is often chosen linear. This method is simple and fast. Another method relies on compartmental modelling. In this case, nonlinear methods are used to estimate parameters of a chosen compartmental model. This method provides generally good results. However, if the data are sparse and noisy, two difficulties can arise with this method. The first one is related to the choice of the suitable compartmental model given the small number of data available in preclinical experiment for instance. Second, nonlinear methods can fail to converge. Much work has been done recently to circumvent these problems (J. Pharmacokinet. Pharmacodyn. 2007; 34:229-249, Stat. Comput., to appear, Biometrical J., to appear, ESAIM P&S 2004; 8:115-131).In this paper, we propose a Bayesian nonparametric model based on P-splines. This method provides good PK parameters estimation, whatever be the number of available observations and the level of noise in the data. Simulations show that the proposed method provides better PK parameters estimations than the interpolation method, both in terms of bias and precision. The Bayesian nonparametric method provides also better AUC and t(1/2) estimations than a correctly specified compartmental model, whereas this last method performs better in t(max) and C(max) estimations.We extend the basic model to a hierarchical one that treats the case where we have concentrations from different subjects. We are then able to get individual PK parameter estimations. Finally, with Bayesian methods, we can get easily some uncertainty measures by obtaining credibility sets for each PK parameter.     

企业执行力的概念模型及其度量方法——基于中国核电企业的实证研究

本文给出了一个关于执行力的确切定义:执行力就是有效率地决定事情并让他人去有效果地具体贯彻实施的能力。在文献综述的基础上,建立了企业执行力的理论模型,假设战略导向型、制度导向型、文化导向型、激励导向型和能力导向型这五种结构变量对企业执行力产生显著影响。通过对12家中国核电企业进行问卷调查,对理论模型进行实证检验。结果表明,企业执行力受到组织学习、组织结构、企业价值、绩效管理、市场营销和人际关系这6个变量的显著影响。通过t检验和方差分析,证明个体特征与组织特征的差异会对自变量和因变量的认知产生显著的差异性,这就为企业领导者和管理者为提升企业执行力而采取针对性较强的管理措施奠定了理论基础。     

Refugee Family Voices: Shelter Needs in Iraqi Kurdistan

The shelter needs of refugees in Iraqi Kurdistan were documented by local government and humanitarian organizations. However, official narratives do not include the “voices” of those directly affected by inadequate shelter: the refugee families themselves. This study uses a mixed‐methods approach to understand the shelter issues experienced by 53 refugee families in Iraqi Kurdistan. Refugee families disclosed seven common shelter problems: water infiltration, lack of public services and schools, inadequate access to water, poor roads, extreme temperatures, need for larger living space and erratic electricity. These families faced an average of three shelter issues, with some dealing with up to five problems at the same time. Families with the highest concentration of shelter issues had higher occurrences of water infiltration, inadequate access to water, extreme temperatures and need for larger living space. The evidence suggests that refugee families are living in worse conditions than those outlined in official narratives.