The duration of unemployment in Russia

This paper uses longitudinal survey data to assess factors affecting the duration of unemployment in Russia. We examine four types of marginalised labour force participants, according to ILO guidelines and survey responses, and we estimate duration models for each type. It turns out that the sets of characteristics with the strongest effects on the duration are remarkably similar across the different unemployment definitions and model specifications. Therefore, despite the formidable practical measurement problems, problematic groups of individuals can actually be identified. Received: 27 January 1999/Accepted: 27 January 2000     

CeO2／蛇纹石体系对饮用水的脱氟行为研究

本文探讨了利用均相沉淀法制备的二氧化铈的脱氟行为,并利用蛇纹石作为载体,对CeO2/蛇纹石体系的除氟行为及最佳条件进行了进一步的研究,结果表明：均相沉淀法得到的二氧化铈除氟效率高,除氟容量可达11.76mg/g。以二氧化铈;蛇纹石为1：10的混合体系的除氟容量大大高于其他方法处理过的蛇纹石体系,其附近氟容量达到0.568mg/g。     

Economic statistical design of the T2 control chart under the Weibull shock model with multiple assignable causes

A proper monitoring of stochastic systems is the control charts of statistical process control and drift in characteristics of output may be due to one or several assignable causes. Although much research has been done on the design of control charts, the economic statistical design of the T2 control chart under the Weibull shock model with multiple assignable causes has not yet been addressed. Therefore, we tried to deal with it in this paper and thus we developed a cost model based on the variable sampling interval. We also give an example to support the practical use of T2 chart under the Weibull shock model with multiple assignable causes. Based on the optimization of the average cost per unit of time and taking into account the different combination values of Weibull distribution parameters, optimal values of design parameters were derived and calculated. Then, the cost models under the influence of single assignable cause and multiple assignable causes under the same cost and time parameters were compared. Also, a sensitivity analysis was conducted in which the variability of loss cost and design parameters due to change of cost and time and Weibull distribution parameters were evaluated.     

Geometric Anisotropic Spatial Point Pattern Analysis and Cox Processes

We consider spatial point processes with a pair correlation function, which depends only on the lag vector between a pair of points. Our interest is in statistical models with a special kind of ‘structured’ anisotropy: the pair correlation function is geometric anisotropic if it is elliptical but not spherical. In particular, we study Cox process models with an elliptical pair correlation function, including shot noise Cox processes and log Gaussian Cox processes, and we develop estimation procedures using summary statistics and Bayesian methods. Our methodology is illustrated on real and synthetic datasets of spatial point patterns.     

A Lower Bound for the Wrap-around L2-discrepancy on Combined Designs of Mixed Two- and Three-level Factorials

The objective of this article is to study the issue of employing the uniformity criterion measured by wrap-around L₂-discrepancy to assess the optimal foldover plans. For mixed two- and three-level fractional factorials as the original designs, general foldover plan and combined design under a foldover plan are defined, and the equivalence between any foldover plan and its complementary foldover plan is investigated. A lower bound of wrap-around L₂-discrepancy of combined designs under a general foldover plan is obtained, which can be used as a benchmark for searching optimal foldover plans. Moreover, it also provides a theoretical justification for optimal foldover plans in terms of uniformity criterion.     

中国M2/GDP水平的国际比较与畸高的成因探析

M2/GDP本是衡量一国经济货币化程度的重要指标.文章通过国际比较发现,中国不但存在M2/GDP持续上升的普遍性问题,而且这一问题相时其他主要经济国家表现得更为异常.造成中国M2/GDP畸高的原因可以归结为货币化论、货币沉淀论及货币反替代论.M2/GDP的比例越高,整体支付风险越大,任由这种局面发展,央行的信用创造能力和银行体系的支付能力都将逐渐蚀空.文章提出提高我国金融配置效率、加快金融体制改革和现行外汇体制改革是有效解决我国M2/GDP畸高的必经之路.     

D-optimal minimax regression designs on discrete design space

One classical design criterion is to minimize the determinant of the covariance matrix of the regression estimates, and the designs are called D-optimal designs. To reflect the nature that the proposed models are only approximately true, we propose a robust design criterion to study response surface designs. Both the variance and bias are considered in the criterion. In particular, D-optimal minimax designs are investigated and constructed. Examples are given to compare D-optimal minimax designs with classical D-optimal designs.     

Sex hormones and choice under risk

We study the correlation of choice under risk in Holt–Laury lotteries for gains and losses with gender, the use of hormonal contraceptives, menstrual cycle information, salivary testosterone, estradiol, progesterone, and cortisol as well as the digit ratio (2D:4D; length of the index finger to the ring finger of the right hand) in more than 200 subjects (45% females). In males, salivary testosterone is negatively correlated with risk aversion for gains only. In females, salivary cortisol is positively correlated with risk aversion for gains only. No other significant correlations between risk preferences and salivary hormones are observed. No significant correlations between risk preferences and the menstrual cycle are observed in naturally cycling females. No significant correlations between risk preferences and the digit ratio are observed in either gender and/or race.     

Business reform outcomes: Why so different?

Post-crisis policy making increasingly focuses on doing business reforms. We argue that the effects of those reforms will be different across countries. To understand the reasons for the reform outcome divergence, we advance a novel firm-size distribution (FSDs) argument. At the center of the argument is the fact that FSDs are different across countries and stable over time. Then, if a given doing business reform induces firms of different size to grow differently, this will produce a variety of reform outcomes across countries. To advance the argument, we set up a tractable general equilibrium (GE) model and study how firms of different size grow after a doing business reform. The model predicts that larger firms will grow faster than smaller firms after the reform. The model predictions are tested on the Enterprise Surveys (ES) data, merged with the Doing Business indicators. We confirm that firms of different size grow differently after a Doing Business reform. Thus, based on the notable differences of firm size distributions across countries, identical reforms to start, operate and close a business will produce a variety of reform outcomes across countries.