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.     

Plantation Slavery and Economic Development in the Antebellum Southern United States

The relationship of plantation slavery in the Americas to economic and social development in the regions it was dominant has long been a subject of scholarly debate. The existing literature is divided into two broad interpretive models –'planter capitalism' (Fogel and Engerman, Fleisig) and the 'pre-bourgeois civilization' (Genovese, Moreno-Fraginals). While each grasps aspects of plantation slavery's dynamics, neither provides a consistent and coherent historical or theoretical account of slavery's impact on economic development because they focus on the subjective motivations of economic actors (planters or slaves) independent of their social context. Borrowing Robert Brenner's concept of 'social property relations', the article presents an alternative analysis of the dynamics of plantation slavery and their relation to economic development in the regions it dominated.     

高校女生体育课堂教学的现状及对策

调查发现女生中只有33．97％对体育课有兴趣，原因是：体育意识不成熟、教材存在重复现象、有严重的心理障碍、没有突破传统的教学方法、课外活动缺乏行之有效的组织管理等。应采取的措施有：明确高校体育教育理念、加强思想教育、改革体育教学模式、合理选择教学内容和方法等。     

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.     

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.