DOES MOTHER'S EDUCATION MATTER IN CHILD'S HEALTH? EVIDENCE FROM SOUTH AFRICA1

Using the 1993 South Africa Integrated Household Survey, this paper studies the effect that mother's education through the knowledge channel has on children's health using height for age Z‐scores as health measure. Under a two‐stage least square methodology we find that an increase in 4 years on mother's education (approximately 1 standard deviation) will lead to an increase of 0.6 standard deviations on her child's height for age Z‐score. We also find, as the medical literature suggests, support for the hypothesis that mother's education is more important for children older than 24 months of age.     

From quality to innovation: Evidence from two French Employer Surveys

In this article we investigate the impact of quality systems on innovation performance using the method of propensity matching. We use two French microeconomic surveys, the “Organizational Changes and Computerization” (COI 1997) and the “Community Innovation Survey” (CIS3 1998–2000). The first hypothesis indicating that quality (ISO 9000 certification) impacts positively on innovation is supported for certain areas of innovation performance. Furthermore, the second hypothesis states that different levels of quality differentially improve innovation performance. Results indicate that the innovation performance of firms with Top Quality Level is higher than that of firms with Medium Quality Level which is also higher than that of firms with Low Quality Level for certain areas of innovation. However, we found that the difference in innovation performance between firms with Medium and Low Quality Levels is not of a great magnitude. This study implies that in order to achieve a significant innovation performance improvement via quality systems, a very well-established quality system is needed within a firm.     

Corrigendum to “On randomized matching mechanisms” [Economic Theory 8(1996)377–381]

Ma (in Econ. Theory 8, 377–381, 1996) studied the random order mechanism, a matching mechanism suggested by Roth and Vande Vate (Econometrica 58, 1475–1480, 1990) for marriage markets. By means of an example he showed that the random order mechanism does not always reach all stable matchings. Although Ma's (1996) result is true, we show that the probability distribution he presented – and therefore the proof of his Claim 2 – is not correct. The mistake in the calculations by Ma (1996) is due to the fact that even though the example looks very symmetric, some of the calculations are not as “symmetric.” We thank two anonymous referees for their helpful comments. B. Klaus’s and F. Klijn’s research was supported by Ramón y Cajal contracts of the Spanish Ministerio de Ciencia y Tecnología. The work of the authors was also partially supported through the Spanish Plan Nacional I+D+I (BEC2002-02130 and SEJ2005-01690) and the Generalitat de Catalunya (SGR2005-00626 and the Barcelona Economics Program of CREA).     

比较分析扩大内需措施

消费是生产的惟一目的，扩大内需是我国经济发展长期基本立足点。文章认为扩大内需首要任务是扩大居民消费，以此为出发点，分析了制约我国居民消费的瓶颈因素，并相应评析了常用扩大内需措施，发现很多措施不利于长期经济健康发展。因此，我国应改变扩大内需的方式，以更宽阔的眼光寻求扩大内需的有效措施，确保国民经济又好又快发展。     

商业银行客户信用评级研究--基于平衡计分卡视角

信贷业务是国内商业银行的主营业务,客户信用评级作为控制商业银行信贷风险的重要一环是商业银行进行授信、贷款审批和贷后管理的基础。客户信用评级体系的开发和完善也成为了当前银行工作的重点。文章基于平衡计分卡的视角,针对当前商业银行客户信用评级管理的现状与不足,从四个方面对评级指标进行选取。同时使用层次分析法对指标体系进行权重分配并设定相应的评分标准和客户信用等级,最后通过案例分析对模型的操作性和有效性进行了验证。文章的评级模型并不同于国外研究论述的数学模型,其在操作上更加简便,信息获取也较为方便,更加适合当前我国商业银行借鉴和使用,因此也在一定程度上对我国商业银行客户信用评级体系的不断完善提供了参考意见。     

Nearly exact sample size calculation for powerful non‐randomized tests for differences between binomial proportions

In the case of two independent samples, it turns out that among the procedures taken in consideration, BOSCHLOO'S technique of raising the nominal level in the standard conditional test as far as admissible performs best in terms of power against almost all alternatives. The computational burden entailed in exact sample size calculation is comparatively modest for both the uniformly most powerful unbiased randomized and the conservative non‐randomized version of the exact Fisher‐type test. Computing these values yields a pair of bounds enclosing the exact sample size required for the Boschloo test, and it seems reasonable to replace the exact value with the middle of the corresponding interval. Comparisons between these mid‐N estimates and the fully exact sample sizes lead to the conclusion that the extra computational effort required for obtaining the latter is mostly dispensable. This holds also true in the case of paired binary data (McNemar setting). In the latter, the level‐corrected score test turns out to be almost as powerful as the randomized uniformly most powerful unbiased test and should be preferred to the McNemar–Boschloo test. The mid‐N rule provides a fairly tight upper bound to the exact sample size for the score test for paired proportions.     

The Influence of Entrepreneurial Risk Assessment on Venture Launch or Growth Decisions

Entrepreneurs are thought to engage in riskier behavior than nonentrepreneurs, yet little empirical evidence supports that intuitively appealing notion. We argue instead that differences in information, not risk aversion, may explain the decision to launch or grow a venture. We separately test risk taking propensity and risk assessment. We hypothesize that entrepreneurs will not differ from nonentrepreneurs on risk taking propensity. Additionally, we propose and test a model of risk assessment. The sample size for this exploratory study is n=53 with 30 respondents declaring themselves as entrepreneurs and 23 declaring themselves as nonentrepreneurs. The study’s design is a simulation. Each respondent is provided with data on a potential acquisition that would result in either the launch of a new venture or significant growth for an existing firm. Consistent with the hypotheses, the results show no difference between entrepreneurs and nonentrepreneurs on the risk taking measure. We also find that we can predict entrepreneurial behavior based on risk assessment. We close with a discussion of limitations and directions for future research.     

Is there really a foreign ownership wage premium? Evidence from matched employer-employee data

Numerous studies on firm-level data have reported higher average wages in foreign-owned firms than in domestically owned firms. This, however, does not necessarily imply that the individual worker's wage increase with foreign ownership. Using detailed matched employer-employee data on the entire Swedish private sector, we examine the effect of foreign ownership on individual wages, controlling for individual and firm heterogeneity as well as for possible selection bias in foreign acquisitions. We distinguish between foreign greenfields and takeovers and compare foreign-owned firms with both domestic multinationals and local firms. Our results show a considerably smaller wage premium in foreign-owned firms than what has been found in studies conducted at a more aggregate level. Moreover, foreign takeovers of Swedish firms tend to have no or even a negative effect on wages.     

股权激励存在持续性的激励效应吗？--基于倾向得分匹配法的实证分析

为克服样本选择偏误,本文采用倾向得分匹配法,在六年的时间框架内检验了股权激励效应的持续性问题。研究发现：整体而言,激励组的ROE和Tobin’s Q值均显著高于控制组,说明股权激励能有效地提高企业的财务绩效和市场价值;激励组的ROE在股权激励计划实施后的三年时间里均显著高于控制组,三年之后逐渐与控制组无显著差异,表明股权激励对企业财务绩效的提升作用能持续三年时间;激励组的Tobin’s Q值在实施的第一年与控制组无显著差异,但在随后的四年时间里均显著高于控制组,表明股权激励对企业市场价值存在长达四年的持续提升作用,但存在为期一年的时滞效应。     

分块自适应图像稀疏分解

针对图像稀疏分解的计算时间复杂度非常高这个问题，提出了分块自适应图像稀疏分解算法。该算法根据稀疏分解计算时间复杂度和待分解图像大小之间的关系。把待分解图像分成互不重叠的小块。然后对每个小块图像进行稀疏分解。根据每一块的复杂程度。自适应地决定稀疏分解的结束。实验结果表明。在分解原子个数相近或相同的条件下。新算法对稀疏分解后重建图像比在整幅图像上进行稀疏分解重建的图像质量下降0．5dB。但计算速度提高了约15倍。