Does trade raise income?: Evidence from the twentieth century

Efforts to estimate the effects of international trade on a country’s real income have been hampered by the failure to account for the endogeneity of trade. Frankel and Romer recently use a country’s geographic attributes — notably its distance from potential trading partners — to construct an instrument to identify the effects of trade on income in 1985. Using data from the pre-World War I, the interwar, and the post-war periods, we find that the main result of Frankel and Romer is confirmed throughout the whole century: countries that trade more as a proportion of their GDP have higher incomes even after controlling for the endogeneity of trade. We also find that the OLS estimate of trade’s effect on income is biased downwards in almost every sample year. However, this result is not robust to the inclusion of distance from equator (latitude).     

人民币汇率购买力平价问题的重新研究——基于结构突变检验与变结构协整的视角

本文应用LM结构突变检验以及Gregory-Hansen等变结构协整方法,对人民币汇率购买力平价问题进行了重新研究。研究发现样本期内人民币汇率发生了两次结构突变,第一次发生在2005年7月,第二次发生在2006年12月。LM检验显示,发生了结构突变的汇率数据生成过程仍为单位根过程,意味着某些经济冲击确实对数据生成过程(DGP)产生了实质影响。进一步对比研究发现,在未考虑结构突变情况下,样本期内购买力平价不成立;但在考虑结构突变情况下,两种变结构协整方法都支持购买力平价成立。     

铁路多经物流的规模经济研究及实例分析

随着物流被列为十大振兴产业革命之一,目前,我国铁路多经物流运输企业正面临着一个十分良好的发展机遇,近年来,不少企业通过各种方式扩大自己的生产经营规模,以取得更好的经营效果。通过运用多元线性回归模型来分析企业的规模经济,分别从理论和实例两个方面相结合进行研究,论证铁路多经物流存在着局部和总体的规模经济,结合此多元线性回归模型分析铁路多经物流由于规模扩大而出现经济的原因。     

基于PCA-SVM的交通事件检测研究

随着自动控制等技术的不断发展,智能事件自动检测系统为高速公路事件检测提供了有效的途径。但传统的检测方法因为交通数据样本有限、输入交通特征过于冗余、参数设置无法达到最优等问题的影响而无法获得更优的性能。文中采用I-880实测数据集,运用主成分分析方法对交通输入特性进行特征选择,构建支持向量机事件检测模型,最后用粒子群算法选择支持向量机模型参数,获得了满意的检测效果,为设计高性能的事件检测算法提供了方法,具有一定的现实意义。     

Combining quality and quantity. A psychometric evaluation of the self-anchoring scale

In this study a psychometric comparison is made between a category rating scale with fixed anchors and a self-anchoring category rating scale where respondents themselves define the end anchors by referring to their personal experiences with the construct being measured. A student-satisfaction questionnaire was administered to 301 undergraduate students on two test moments separated by a 1-month period. Both types of category rating scales were crossed with both test moments according to a 2 ×  2 mixed factorial design. Our results show that respondents perceive the construct being measured in the same way with both rating scales. A comparison concerning different indicators of reliability, i.e. test–retest reliability, internal consistency and the error variances associated with each item, also failed to find a difference between both rating scales. In a last analysis it is demonstrated that using a self-anchoring rating scale or a rating scale with fixed anchors has a small but significant effect on the ratings of the respondents. In conclusion, a self anchoring scale may be the scale of choice if additional qualitative information from the anchors is warranted, but when quantitative comparisons between groups are required, rating scales with fixed anchors are preferable thanks to their ease of use.     

Rethinking determinants of ICT acceptance: Towards an integrated and comprehensive overview

In the contemporary ICT environment, we are confronted with a growing number of failing innovations. New technological innovations often fail because too much attention is still given to (technical) product-related features without taking into account the most important parameters of user acceptance. In addition, suppliers of ICT products often lack accurate insight into the distinguished profiles of their (potential) target audience. In this article theoretical considerations and empirical results on this matter are highlighted. First of all, an approach is proposed in which more traditional and often scattered vision(s) on adoption determinants are broadened into an integrated framework. The approach provides a stronger base for better targeting of (new) users of technologies. Secondly, the authors elaborate on this by rethinking these determinants with regard to later adopters. Later adopters (or even non-adopters/users) are often ignored in technology acceptance research. However, especially for policy purposes, the understanding of why people do not adopt or do not use ICT is strongly relevant in the light of the development of an inclusive information society. Both approaches are illustrated by case studies starting from a common list of nineteen ICT appropriation determinants. This framework enables to better profile both earlier and later adopters as well as it allows to formulate recommendations how to bring innovations in the market. Summarizing, this contribution offers an integrated approach on technology acceptance research by bridging the gap between a market and a policy-oriented point of view.     

A model for R&D performance measurement

R&D activities are increasingly costly and risky and, as a consequence, measuring their performance and contribution to value becomes critical. This paper illustrates a formal model for measuring R&D performance, based upon a balanced and synthetic evaluation of quantitative indicators from five different perspectives of performance: financial, customer, innovation and learning, internal business, alliances, and networks. The model is built in coherence with the suggestions coming from the theory of measurement in soft systems, which gives relevant guidelines for ensuring validity, objectivity and inter-subjectivity of the model. Then, an application in a real R&D setting is described, which helps to understand the model and to enlighten its main advantages and limits.     

政策测量、政策协同与经济绩效——基于创新政策的实证研究(1978-2006)

通过量化后的政策,本文测量了政策之间的协同问题,并利用扩展的柯布—道格拉斯生产函数研究了政策协同与经济绩效之间的关系。文章的主要贡献在于给出了政策量化标准具体的操作手册,并得出一些新的结论:第一,经济增长与政策力度强相关;第二,技术引进与消化吸收的政策目标协同对经济绩效没有贡献,原因在于两者协同在政策层面的缺失;第三,财政税收与行政措施的协同对经济绩效具有显著的削弱作用,而金融外汇与行政措施的协同对经济绩效有显著的促进作用。     

The information in the term structure of German interest rates

This paper tests the Expectations Hypothesis (EH) of the term structure of interest rates using new data for Germany. The German term structure appears to forecast future short-term interest rates surprisingly well, compared with previous studies with US data, while it has lower predictive power for long-term interest rates. However, the direction suggested by the coefficient estimates is consistent with that implied by the EH, that is when the term spread widens, long rates increase. The use of instrumental variables to deal with possible measurement errors in the data significantly improves regressions for the long rates. Moreover, re-estimation with proxy variables to account for the possibility of time-varying term premia confirms that the evolution of both short and long rates corresponds to the predictions of the EH and that most of the information is in the term spread. These results are important as they suggest that monetary policy in Germany could be guided by the slope of the term structure.     

《互换性与测量技术基础》课程改革初探

《互换性与测量技术基础》是机械类专业的重要技术基础课。针对该课程特点,结合教学实践,着重在教学方法、课程改革方面提出一些观点。