密封胶在拉索索端结构中的应用研究

索端结构是拉索的防护薄弱环节,在索端结构中增加密封胶措施是索端密封的一次探索。选取了几种不同的密封胶分别与拉索聚乙烯护套进行粘结,对提高斜拉索的耐久性和安全性有一定的意义。     

A choice experiment on fuel taxation and earmarking in Norway

Pigouvian taxes are efficient — but unpopular among voters — and hence often politically infeasible. Earmarking of revenues has been widely reported to increase public support for taxes, but earmarking is generally not the most efficient use of the revenues. This trade-off between efficiency and political feasibility is the motivation for our primary research objective: to quantify the effect of earmarking on support for fuel tax rises. Our secondary research objective is to investigate why earmarking increases support. Using data from a representative sample of the Norwegian voter population (N = 1147), we estimate models of voter preferences for fuel taxes using logistic regression models. Our results show that, in the absence of earmarking, the majority of voters would like to reduce fuel taxes, but earmarking the revenues for environmental measures has a substantial effect on voter support for fuel tax increases, garnering a majority for increases of up to 15% above present levels. Further analysis indicates that a prime reason why earmarking for environmental measures is popular is that it increases the perceived environmental effectiveness of the tax, and hence its legitimacy as an environmental rather than a fiscal policy instrument.     

电工学实验教学改革研究与实践

电工学课程是高校非电专业开设的一门实践性很强的技术基础课,而电工学实验教学是电工学课程教学中的重要环节。深化电工学实验教学改革,完善电工学实验教学体系,有利于培养学生创新意识和工程实践能力。     

宏观经济波动、公司规模和资本结构选择

中国宏观经济2006—2008年的波动为资本结构自然实验法研究提供了条件。选择该期间行业内资产规模最大和最小的中国A股上市公司作为研究样本,实证研究了宏观经济波动对不同规模上市公司资本结构选择的影响。研究发现:宏观经济波动对大规模上市公司和小规模上市公司的资本结构影响存在显著差异,不同规模的公司均显著改变了其融资行为;宏观经济状况和公司规模是上市公司资本结构选择的重要因素。     

Field Experiments in a Course on Behavioral Economics: Nudging Students Around Campus

In experiential education, the student learns through experience by observing a concept or phenomenon and applying this knowledge in a real-world context. A research project conducted by undergraduate students at a U.S. private liberal arts college is described in this article. The project provided opportunity for students to think about their decision-making processes, compare them to existing literature, and apply this knowledge in examining their own hypotheses through primary data collection on campus. While the research design's simplicity ensured that the project could be completed in time for a final grade and sacrificed lecture material in favor of feedback opportunities, this behavioral field experiment was a rewarding experience because of students’ enthusiasm and their ability to defend and think critically of their own ideas.     

Does an economic incentive affect provider behavior? Evidence from a field experiment on different payment mechanisms

Aims: This study analyzed discrepancies in the quantity of medical services supplied by physicians under different payment systems for patients with different health statuses and illnesses by means of a field experiment.

Methods: Based on the laboratory experiment of Heike Hennig-Schmidt, we designed a field experiment to examine fee-for-service (FFS), capitation (CAP), and diagnosis-related group (DRG) payment systems. Medical students were replaced with 220 physicians as experimental subjects, which more closely reflected the clinical choices made by physicians in the real world. Under the three payment mechanisms, the quantity of medical services provided by physicians when they treated patients with different health statuses and illnesses were collected. Finally, relevant statistics were computed and analyzed.

Results: It was found that payment systems (sig. = 0.000) and patient health status (sig. = 0.000) had a stronger effect on physicians’ choices regarding quantity of medical services than illness types (sig. = 0.793). Additionally, under the FFS and CAP payment systems, physicians overserved patients in good and intermediate health while underserving patients in bad health. Under the DRG payment system, physicians overserved patients in good health and underserved patients in intermediate and bad health. Correspondingly, under FFS and CAP, the proportional loss of benefits was the highest for patients in bad health and the lowest for patients in good and intermediate health; while under DRGs, patients in good and intermediate health had the largest and smallest loss of benefits, respectively.

Limitations: In order to increase external effects of experiment results, we used the field experiment to replace laboratory experiment. However, the external effects still existed because of the blurring and abstraction of the parameters.

Conclusions: Medical treatment cost and price affected the quantity of medical services provided by physicians. Therefore, we proposed that a mix of payment systems could address the common interests of physicians and patients, as well as influence incentives from payment systems.     

TOOLS FOR RE‐RANDOMIZATION

With the rising popularity of field experiments in economics, re‐randomization schemes have emerged as tools to induce balance in observable variables across treatment groups. However, re‐randomization is not fully understood and the methodologies to estimate its effects on the distribution of parameters are still under‐developed. This paper helps to close that gap by suggesting an asymptotically normal re‐randomization scheme and bootstrapping procedure to carry inference under a wide range of estimators and re‐randomization schemes.     

生物工程大实验课程改革与探讨

生物工程大实验是生物工程专业的一门重要的综合性实验课程,就当前生物工程大实验教学存在的几点问题,从实验内容、实验体系、实验方法、考核方式方面对生物工程大实验进行改革与探讨。     

加强实验教学,培养学生实验技能和综合素质

为了提高学生的动手能力,启迪学生严谨科学的思维方法,培养学生的创新意识和实践能力,我们在植物生理生化实验教学中进行了努力的探索。通过加强实验教学,学生具备了更强的科学研究的实验技能,学生的综合素质也有较大的提高,教学效果得到社会、学校和学生的认同,较好地完成了实验教学的主要任务。     

Performance pay and worker cooperation: Evidence from an artefactual field experiment

We report the results of an artefactual field experiment with bicycle messengers in Switzerland and the United States. Messenger work is individualized enough that firms can choose to condition pay on it, but significant externalities in messenger behavior nonetheless give their on-the-job interactions the character of a social dilemma. Second-mover behavior in our sequential prisoner's dilemma allows us to characterize the cooperativeness of our participants. Among messengers, we find that employees at firms that pay for performance are significantly less cooperative than those at firms that pay hourly wages or who are members of cooperatives. To examine whether the difference is the result of treatment or selection we exploit the fact that firm type is location-specific in Switzerland and that entering messengers must work in performance pay firms in the U.S.