Bitcoin price and its marginal cost of production: support for a fundamental value

This study back-tests a marginal cost of production model proposed to value the digital currency Bitcoin. Results from both conventional regression and vector autoregression (VAR) models show that the marginal cost of production plays an important role in explaining Bitcoin prices, challenging recent allegations that Bitcoins are essentially worthless. Even with markets pricing Bitcoin in the thousands of dollars each, the valuation model seems robust. The data show that a price bubble that began in the Fall of 2017 resolved itself in early 2018, converging with the marginal cost model. This suggests that while bubbles may appear in the Bitcoin market, prices will tend to this bound and not collapse to zero.     

The government revenue and government expenditure nexus: empirical evidence from nine Asian countries

The nexus between government revenue and government expenditure has been an important topic in public economics. In this paper, we investigate evidence for cointegration and causality between government revenue and government expenditure for nine Asian countries. We use the recently developed bounds testing approach to cointegration and the conventional F-test to examine Granger causality. Our empirical results suggest that for three out of the nine countries government revenue and government expenditure are cointegrated. Our results on the direction of causation are mixed: (a) for Indonesia, Singapore, Sri Lanka in the short-run and for Nepal in both the short- and long-run we find support for the tax-and-spend hypothesis; (b) Indonesia and Sri Lanka are in conformity with the spend-and-tax hypothesis in the long-run; and (c) for other countries there is evidence of neutrality.     

The Importance of Professional Training for Test Writers

The importance of language testing is noticed by more and more people.But the quality of testing,or say,the level of test writers,has been ignored for a long time.This article intends to talk about the importance of professional training for test writ- ers,in order to arouse people＇s attention to the quality of test designers.     

三线铁路荷载作用下箱梁桥荷载横向分布系数

文章运用有限元程序对三线铁路预应力混凝土连续箱梁桥进行了模拟,分析了三线铁路荷载作用下箱梁的受力特性及在各种荷载工况下荷载横向分布规律,给出了荷载横向系数的实用值。     

浅谈基础英语的测试

在教授基础英语中,无论采用何种教学方法,教学过程中的测试,是考查教学效果的一个手段,也是教学中的重要 环节。本文着重对测试的认识以及运用等进行了论述。     

Drug testing in the transportation industry: The maritime case

The maritime industry provides an interesting case study of the design and implementation of drug-testing programs in the transportation industry during the 1980s. It is clear that such programs were designed and implemented less because of empirical evidence of safety problems than for political reasons. The results in the maritime industry are indicative of a program that is expensive to operate, intrusive with regard to employee privacy, and which will have little or no impact on safety. Focusing such programs on the issue of impairment rather than on the issue of drug usage per se is likely to improve the outcome of the programs. Although, despite common belief, there is little evidence that drug usage or the “drug problem” in U.S. society as a whole had gotten worse in the preceding years (Schonsheck, 1989, 250–251).     

On Testing for the Nullity of Some Skewness Coefficients

Three tests for the skewness of an unknown distribution are derived for iid data. They are based on suitable normalization of estimators of some usual skewness coefficients. Their asymptotic null distributions are derived. The tests are next shown to be consistent and their power under some sequences of local alternatives is investigated. Their finite sample properties are also studied through a simulation experiment, and compared to those of the √ b ₂-test.     

外推型预期公式的检验与评价

经济学中的很多变量需要预测,其中的一个方法是运用外推型预期公式。由于外推型预期公式有 其自身特点和规律,即趋势值的选择是影响预测效果的一个主要变量,因此使用该公式进行经济预测时, 短期预测应选择较小的趋势值,长期预测应选取中间的趋势值。     

Canadian and American Reactions to Drug and Alcohol Testing Programs in the Workplace

We investigated U.S. and Canadian reactions to workplace drug and alcohol testing programs. Canadian truck drivers (n = 183) deemed drug and alcohol testing policies less fair, and were less accepting of these policies, than their American counterparts (n = 153). We also compared the perspectives of recipients versus third-party observers with regard to their reactions to a drug testing program. Unlike the pattern observed among American observers, the responses by Canadian observers were highly similar to those of the recipients. Canadian observers were more inclined to file a formal protest regarding the implementation of a drug and alcohol testing program than were U.S. observers. The results also showed that procedural and interactional justice principles contributed to the program's fairness, acceptance, and lower levels of protest intentions in both Canada and the United States. We propose that scholars and practitioners can gain a better understanding of multinational reactions to drug and alcohol testing by considering not only cultural but also historical, social, political, and other environmental factors that can shape reactions to personnel practices.     

物流配送系统中的运筹学问题及方法研究

物流配送系统中包含诸多运筹学问题,如配送中心选址中的0-1规划问题,货物配载中的背包问题,配送路线优化中的动态规划问题等,通过建立数学模型,利用运筹学方法与信息技术的结合可对上述问题加以解决,为配送业务的进一步发展提供帮助.