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.     

Incremental costs associated with myocardial infarction and stroke in patients with type 2 diabetes mellitus: an overview for economic modeling

Objective:

To identify cost estimates related to myocardial infarction (MI) or stroke in patients with type 2 diabetes mellitus (T2DM) for use in economic models.

Methods:

A systematic literature review was conducted. Electronic databases and conference abstracts were screened against inclusion criteria, which included studies performed in patients who had T2DM before experiencing an MI or stroke. Primary cost studies and economic models were included. Costs were converted to 2012 pounds sterling.

Results:

Fifty-four studies were identified: 13 primary cost studies and 41 economic evaluations using secondary sources for complication costs. Primary studies provided costs from 10 countries. Estimates for a fatal event ranged from £2482–£5222 for MI and from £4900–£6694 for stroke. Costs for the year a non-fatal event occurred ranged from £5071–£29,249 for MI and from £5171–£38,732 for stroke. Annual follow-up costs ranged from £945–£1616 for an MI and from £4704–£12,926 for a stroke. Economic evaluations from 12 countries were identified, and costs of complications showed similar variability to the primary studies.

Discussion:

The costs identified within primary studies varied between and within countries. Many studies used costs estimated in studies not specific to patients with T2DM. Data gaps included a detailed breakdown of resource use, which affected the ability to compare data across countries.

Conclusions:

In the development of economic models for patients with T2DM, the use of accurate estimates of costs associated with MI and stroke is important. When country-specific costs are not available, clear justification for the choice of estimates should be provided.     

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.     

B2C电子商务模式下的物流配送研究

物流配送是电子商务运作的一个重要环节,在整个商务活动中起着举足轻重的作用.目前,在线交易中的信息流已通过互联网基本实现,资金流的安全也在一定程度上得到了解决,但物流仍是电子商务开展的一大瓶颈.B2C作为电子商务的运作模式之一,存在着配送不及时、配送成本高、无法送货等问题.不解决物流配送的问题,B2C模式就难以快速发展.本文针对B2C模式的特点和对物流配送的要求,提出了B2C电子商务模式下建立物流配送系统的解决思路。     

双边政治关系、制度质量与中国对外直接投资*

本文利用中国与其他国家在联合国大会决议的投票行为作为双边政治关系的代理变量,以中国对89个国家2003—2015年对外直接投资数据为样本,分析了双边政治关系对中国对外直接投资的影响。研究表明：整体而言,中国的对外直接投资会受到双边政治关系的显著影响,政治关系的亲密有利于中国对外直接投资的增加。东道国制度质量可以降低中国对外直接投资对双边政治关系的敏感度,且制度质量的调节只能在中国对比自己制度质量高的国家投资时发挥作用。以2008年为分界点,后危机时代双边政治关系对投资的影响更加显著,双边政治关系的经济效应也会显著地受到东道国制度质量的调节。此外,中国改善与“一带一路”沿线国家的政治关系,可以促进中国的对外直接投资。     

Earnings inequality and the informal economy

We analyse the extent and evolution of informality and inequality in the Serbian labour market between 2002 and 2007, using data from the Living Standard Measurement Surveys. Two surprising results emerge. First, the level of informal employment has risen significantly over the period, despite strong economic growth and the introduction of a range of market‐oriented reforms. Secondly, the level of inequality in earnings seems to have remained more or less constant over the period, in contrast to the experience of other countries at a similar stage of transition. We show that informal employees earn significantly less than those in the formal sector, controlling for a range of other variables, and informality plays an increasingly important role in explaining earnings inequality.     

Status of CO2 emissions; driving forces and mitigation countermeasles of Tianjin, China

Climate change is a long-term and important challenge facing the whole world. Mitigation of CO2 emissions is one of important measures responding to climate change. The task of responding to climate change facing each city is very urgent. The total amount of Tianjin City＆#39;s CO2 emissions from energy use and industrial processes is large and the amount of CO2 emissions per capita from fossil fuel combustion is quite high. Mitigation of CO2 emission in Tianjin City encounters many difficulties such as increasing population, rapidly growing economy, heavy industrial structure, backward tertiary industry, low level of energy efficiency and product technologies, and energy structure relying mainly on coal. This paper analyzes Tianjin City＆#39;s general situation of economic and social developments, estimates Tianjin City＆#39;s status of CO2 emissions using 2006 IPCC Guidelines for National Greenhouse Gas Inventories, analyzes Tianjin City＆#39;s driving forces of CO2 emissions by methodology to analyze the driving forces of energy-related CO2 emissions, and puts forward countermeasures mitigating CO2 emissions in Tianjin City, such as strictly controlling increasing population, expediting industrial structure adjustment, insisting on strategy of energy conserving, vigorously enhancing energy efficiency, exploiting and using clean and renewable energy, advancing energy structure adjustments, and actively developing carbon capture and storage （CCS） technologies.     

“2＋1”工学结合工作站管理顶岗实习“1”的模式初探——以常州机电职业技术学院“2＋1”工学结合为例

推行工学结合,加大高职大学生实习的力度,是贯彻国家教育方针、路线、政策的重要举措之一。常州机电职业技术学院实施“2＋1”工学结合工作站管理学生的顶岗实习,即承担三年制高职最后“1”的教学、教育、管理,作为一种模式,是一种探索,也是一种创新。     

P2P运营模式探微

近年来,伴随着网络的全球化发展,P2P企业开始在国外和我国出现,P2P信贷模式也逐渐得到人们的高度关注。但是,由于P2P模式是新兴事物,目前理论界对其所进行的系统研究是十分缺乏的。本文通过对中外典型P2P企业的调查归纳,对P2P企业运营模式进行了系统化的微观探索。     

中国B2C电子商务应用模式差异性分析

本文首先列举当前我国常见的四种B2C类型:综合型B2C、垂直型B2C、工厂网络直销型B2C和平台型B2C,阐述了各种模式的基本概念和适用对象,然后从典型代表的实际应用出发,对各种模式的优缺点进行剖析.最后针对其存在的问题,提出解决问题的思路和方法,以期帮助各种B2C模式在未来的市场竞争中取得更多的优势.