Learning Why More Learning Takes Place in Some Classrooms Than Others

Abstract. The relatively poor average performance of German students on the recent PISA international evaluations of 15- and 16-year-olds' literary skills (2000) and mathematical skills (2003) and the wide variation in performance, with low-income students scoring particularly poorly, have led to calls for reforms of the German educational system. Understanding why students in some classrooms learn more than do those in other classrooms is an important first step in considering alternative reform strategies. Possible explanations include differences in teacher quality, class sizes and peer groups, and also differences among the types of secondary schools that parents select for their children. This paper illustrates a set of techniques that are useful in examining the roles these factors play in predicting why, net of family background and prior achievement, the average achievement of children in some classrooms is much higher than that of children in other classrooms. We illustrate the use of these techniques with a dataset from Bogotá, Colombia, that has two attractive properties. First, some teachers teach multiple classes of students. Second, students are enrolled in schools in two sectors (public and private). Application of the techniques described in this paper could shed light on the reasons why the average academic achievement of German students attending some schools is much higher than that of German students attending other schools.     

高校智力资本运作效率的数据包络分析

文章在综合分析高校智力资本的基本概念和主要内容的基础上，提出了用数据包络分析方法评价高校智力资本运作效率的基本思路与方法，并以8所高校在同一学科中的智力资本运作情况为算例，对数据包络分析的算法和所使用的计算工具作了说明。     

C2C交易中消费者购物心理研究

目前我国经常上网购物人数和网民上网购物比例不断增大，消费者对消费者之间的电子商务交易（C2C）也在迅速发展。对于C2C交易中的卖家而言，掌握消费者在C2C交易中的购物心理对提高销售业绩显得特别重要。文章对消费者在C2C交易中的购物心理进行研究。     

B2B电子商务模式的探讨

针对B2B模式将成为未来电子商务发展的主流,文章先从价值链角度分析了B2B电子商务模式对价值链上游的冲击,然后概括性地总结了目前主要的3种B2B电子商务模式,最后用“SWOT”战略评估方法分析了基于供应链管理的区域型B2B电子商务新模式。     

Corporate Restructuring in Japan Part I: Can M‐Form Organization Manage Diverse Businesses?

The purpose of this paper is to examine the recent organizational restructuring in Japan in the framework of organizational economics, assuming that the product/market portfolio of the firm is fixed. How does a firm set about organizing its internal divisions? I first summarize some stylized facts on corporate diversification strategy and multi‐divisional (M‐form) organization in large Japanese firms from different perspectives. I then analyse the problem of choosing an organizational form. In particular, I argue that, precisely because of its related diversification, the multi‐business Japanese firm adopting the M‐form finds it difficult to differentiate its diverse businesses internally.     

Delays and equilibria with large and small information in social learning

The general model of social learning with irreversible investment and endogenous timing is analyzed for any distribution of private informations. Strategic complementarities and multiple equilibria appear which are generated solely by information externalities. Different equilibria generate strikingly different amounts of information. The impacts of various assumptions (bounded beliefs, large number of agents, discrete time and short periods) are examined carefully. The properties are robust to the introduction of observation noise with a continuum of agents.     

控制火电厂二氧化硫排放的有效途径——排污权交易

目前,我国工业二氧化硫排放量中有42%是火电厂排放的,因此高效控制火电厂的二氧化硫排放是提高空气质量的主要途径。美国利用排污权交易治理火电厂的二氧化硫排放取得了巨大的成功,不仅二氧化硫排放量大幅下降,而且排污权交易也被证明是成本最低的方法。借鉴美国的经验,可以为我国治理火电厂二氧化硫排放提供高效途径。     

基于BP神经网络的我国M2/GDP预测与对策

本文计算了1993年至2005年我国M2/GDP,发现该数据总体呈上升趋势,这一定程度上反映了我国体制上的深层次问题。另外,本文运用带有动量项和自适应学习率的BP神经网络方法预测出我国2006年的M2/GDP是1.6386左右,并提出了一些相应的政策建议。     

中国股市市盈率分布特征及国际比较研究

本文对市盈率的内涵、计算方法、区间确定等理论问题进行了剖解 ,针对中国股市流通股、非流通股并存等特征 ,对市盈率在中国股市的计算方法进行了分析 ;在此基础上对中国股市市盈率分布特征进行实证分析和国际比较研究 ,认为目前沪深股市泡沫成份已较少 ,市盈率在合理区间之内 ,中国股市具有投资价值     

On the forecastability of share prices on the Viennese stock exchange

In this paper the Viennese stock exchange data are analysed by using ARMA and GARCH technology. After using AIC and BIC for estimating the linear structure of the time series, to the resulting innovations a GARCH(1,1) model is fit. The resulting residuals are then tested for serial independence and constancy of its distribution to check whether the models are reasonable. Main result is that the residuals of this ARMA-GARCH(1,1)-model are reasonably iid (which is checked by BDS and classical independence tests) for index data and significantly less well-behaved for stock data. Second, there is considerable autocorrelation in the data (especially in the Viennese indices WBK and ATX) which can be exploited even with 1.25% transaction costs (which is checked by a posteriori analysis of a strategy which exploits an underlying time-varying AR(1) model), however, much higher profit can be made with 0.5% transaction costs. Furthermore, the same techniques are applied to US Standard & Poor 500 index and the results for both data sets are compared giving the result that the US-market looks much more mature than the Viennese one.Financial Support by the Institute for Advanced Studies, Vienna, and the Fonds zur Förderung der wissenschaftlichen Forschung, Vienna, Grant P 9176 is gratefully acknowledged. This paper is a slightly abbreviated version of the Research Report No. 135 by the same authors (see References), which contains many detailed plots of the results.