Equivalence of Input Quotas and Input Charges under Asymmetric Information in Agri‐environmental Schemes

A model of adverse selection and moral hazard in agri‐environmental schemes is developed based on the input quota mechanism of Moxey et al. (Journal of Agricultural Economics, Vol. 50, (1999) pp. 187–202) and Ozanne et al. (European Review of Agricultural Economics, Vol. 28, (2001) pp. 329–347), rather than the input charge mechanism of White (Journal of Agricultural Economics, Vol. 53, (2002) pp. 353–360), but the variable fine of the latter rather than the fixed fine assumed by Ozanne et al. (European Journal of Agricultural Economics, Vol. 28, (2001) pp. 329–347) is used. Incentive‐compatible contracts, including the optimal probabilities of detection (and, therefore, monitoring frequencies and costs) for more and less efficient farmers, are identified. It is shown that the input charge and input quota approaches lead to identical outcomes – in terms of abatement levels, compensation payments, monitoring costs and probabilities of detection – confirming the equivalence of input quotas and input charges under asymmetric information. It is also shown that the optimal contracts are independent of the risk preferences of farmers with regard to being caught cheating.     

介绍新标准与原标准的异同

介绍１９９６年新系列形状和位置公差国家标准与原标准的异同。     

Are OTT messaging and mobile telecommunication an interrelated market? An empirical analysis

OTT messengers such as Facebook and WhatsApp have gained wide popularity among mobile users while the traffic of text messaging is in strong decline. As such, there is a debate over whether both services are interrelated and constitute a joint product market, which has important implications for the current wave of mergers in the mobile industry and regulation policy. To the best of our knowledge, this work is the first to provide an empirical analysis of how the consumption of OTT messengers affects demand for text messaging and mobile voice services. We make use of an innovative dataset which includes very detailed information on smartphone usage in Norway and consider a novel approach to address this question which is embedded in the complexity of two-sided markets. Interestingly, our findings suggest that OTT messengers complement demand for traditional mobile telecommunication services for this context. Consequently, both markets are interrelated but do not constitute a joint market from the perspective of competition policy in Norway. Moreover, we find an explanation for why reductions of text messaging usage have been so drastic in some countries and an analogous development for mobile voice is rather unlikely. Finally, our empirical results provide a new perspective on the modelling of consumer utility in communication networks in the theoretical literature.     

Moral Hazard,Targeting and Contract Duration in Agri‐Environmental Policy

This article extends the multi‐period agri‐environmental contract model of Fraser (Journal of Agricultural Economics, Vol. 55 , (2004) pp. 525–540) to include a more realistic specification of the inter‐temporal penalties for non‐compliance, and therefore of the inter‐temporal moral hazard problem in agri‐environmental policy design. It is shown that a farmer has an unambiguous preference for cheating early over cheating late in the contract period based on differences in the expected cost of compliance. It is then shown how the principal can make use of this unambiguous preference to target monitoring resources intertemporally, and in so doing, to encourage full contract duration compliance.     

Exact and asymptotic tests for possibly non-regular hypotheses on stochastic volatility models

We study the problem of testing hypotheses on the parameters of one- and two-factor stochastic volatility models (SV), allowing for the possible presence of non-regularities such as singular moment conditions and unidentified parameters, which can lead to non-standard asymptotic distributions. We focus on the development of simulation-based exact procedures–whose level can be controlled in finite samples–as well as on large-sample procedures which remain valid under non-regular conditions. We consider Wald-type, score-type and likelihood-ratio-type tests based on a simple moment estimator, which can be easily simulated. We also propose a C(α)-type test which is very easy to implement and exhibits relatively good size and power properties. Besides usual linear restrictions on the SV model coefficients, the problems studied include testing homoskedasticity against a SV alternative (which involves singular moment conditions under the null hypothesis) and testing the null hypothesis of one factor driving the dynamics of the volatility process against two factors (which raises identification difficulties). Three ways of implementing the tests based on alternative statistics are compared: asymptotic critical values (when available), a local Monte Carlo (or parametric bootstrap) test procedure, and a maximized Monte Carlo (MMC) procedure. The size and power properties of the proposed tests are examined in a simulation experiment. The results indicate that the C(α)-based tests (built upon the simple moment estimator available in closed form) have good size and power properties for regular hypotheses, while Monte Carlo tests are much more reliable than those based on asymptotic critical values. Further, in cases where the parametric bootstrap appears to fail (for example, in the presence of identification problems), the MMC procedure easily controls the level of the tests. Moreover, MMC-based tests exhibit relatively good power performance despite the conservative feature of the procedure. Finally, we present an application to a time series of returns on the Standard and Poor’s Composite Price Index.     

面对新的检测要求 机动车检测站应对措施

国家标准GB21861-2008将于2009年6月1日开始实行,届时现行公共安全行业标准GA468-2004<机动车安全技术检验项目和方法>将自动废止,不再实施,为了读者更好掌握新标准,保证新标准的落实执行,我们将新旧标准主要不同之处和安检机构为了适应新标准而应修改变更之处作主要的综合总结.     

国务院决定给予企业集团5方面优惠政策

国务院决定给予企业集团５方面优惠政策１、着重突破部门、地方所有制“三不变”的束缚，理顺计划单列体制；２、建立有竞争机制的领导体制，其中包括以下凡种形式：（１）由国家或省设立派出机构─—董事会或管委会，实行对计划单列企业集团的领导；（２）股份制核心企业...     

汇编语言差异比较——从X86到ARM

文章从5个方面比较了教学中普遍采用的两种CPU——X86 CPU和ARM CPU的差异。X86作为典型的CISC计算机汇编语言,指令系统复杂,主要应用于通用计算机中。ARM采用嵌入式系统中广泛采用的RISC结构,多应用于嵌入式领域。只有采用比较的学习方法才能更好地掌握不同处理器的特点及应用需求,更有利于实际的系统开发。     

BUSINESS AND FINANCIAL METHOD PATENTS, INNOVATION, AND POLICY

Court decisions in the 1990s are widely viewed as having opened the door to a flood of business method and financial patents at the US Patent and Trademark Office, and to have also impacted other patent offices around the world. A number of scholars, both legal and economic, have critiqued both the quality of these patents and the decisions themselves. This paper reviews the history of business method and financial patents briefly and then explores what economists know about the relationship between the patent system and innovation, in order to draw some tentative conclusions about their likely impact. It concludes by finding some consensus in the literature about the problems associated with this particular expansion of patentable subject matter, highlighting the remaining areas of disagreement, and reviewing the various policy recommendations.     

Principles of Tax Design,Public Policy and Beyond: The Ideas of James Mirrlees, 1936–2018

Sir James Mirrlees, co‐recipient of the 1996 Nobel Memorial Prize in Economic Sciences, passed away in August 2018. This article outlines how his work has transformed economists’ understanding of their discipline – from the principles of tax design to the theory of contracts and beyond. By conceiving of policy questions in terms of information asymmetries between governments and taxpayers, Mirrlees demonstrated how to conduct convincing analysis of redistributive objectives together with incentive effects in the design of general tax systems and public policy more broadly. His ability to simplify complex problems in ways that reveal their tractable essence means that his work has yielded insights that have reverberated throughout the discipline. It has also proved highly fruitful for practical policy design.