Estimation in conditional first order autoregression with discrete support

We consider estimation in the class of first order conditional linear autoregressive models with discrete support that are routinely used to model time series of counts. Various groups of estimators proposed in the literature are discussed: moment-based estimators; regression-based estimators; and likelihood-based estimators. Some of these have been used previously and others not. In particular, we address the performance of new types of generalized method of moments estimators and propose an exact maximum likelihood procedure valid for a Poisson marginal model using backcasting. The small sample properties of all estimators are comprehensively analyzed using simulation. Three situations are considered using data generated with: a fixed autoregressive parameter and equidispersed Poisson innovations; negative binomial innovations; and, additionally, a random autoregressive coefficient. The first set of experiments indicates that bias correction methods, not hitherto used in this context to our knowledge, are some-times needed and that likelihood-based estimators, as might be expected, perform well. The second two scenarios are representative of overdispersion. Methods designed specifically for the Poisson context now perform uniformly badly, but simple, bias-corrected, Yule-Walker and least squares estimators perform well in all cases.     

资源型城市中小企业技术创新支撑体系研究

资源型城市是我国城市类型中十分重要的一类城市,而中小企业在技术创新和经济发展中具有特殊的地位。该文重点从技术支撑体系、融资服务支撑体系、人力资源支撑体系、信息支撑体系、创新政策支撑体系、社会中介服务体系等几个方面,对中小企业技术创新的外部支持进行探讨。     

A simple theory of ‘meso’. On the co-evolution of institutions and platform size—With an application to varieties of capitalism and ‘medium-sized’ countries

This paper deals with institutional emergence in the well-known ‘evolution of cooperation’ framework and focuses on its size dimension. It is argued that some ‘meso’ (rather than ‘macro’) level (to be numerically determined) is the proper level of cultural emergence, diffusion, and retention. Also Schumpeterian economists (K. Dopfer et al.) have discussed institutions as ‘meso’ phenomena, and Schelling, Axelrod, Arthur, Lindgren, and many others have dealt with ‘critical masses’ of coordinated agents, including related segregations of populations. However, the process and logic of emergent group size has rarely been explicitly explored so far. In this paper, ‘meso’ will be explained, in an evolutionary and game–theoretic frame and a population perspective, in terms of a cooperating group smaller than the whole population involved. Mechanisms such as memory, monitoring, reputation chains, and active partner selection will loosen the total connectivity of the deterministic ‘single-shot’ benchmark and thus allow for emergent ‘meso’-sized arenas, while expectations to meet a cooperative partner next round remain sufficiently high. Applications of ‘meso-nomia’ include the deep structure of ‘general trust’ and the surprisingly high macro-economic and macro-social performance in ‘small’ and ‘well-networked’ countries which helps to explain persistent ‘varieties of capitalism’. A strategy for empirical application of the theoretical approach and some first empirical indications of its relevance are presented.     

天津市科技型中小企业股权激励模式的选择

知识型员工是科技型中小企业核心人力资源,实施股权激励的对象。依据天津市科技型中小企业发展的基本特征,本文对科技型中小企业实施知识型员工股权激励机制的模式选择进行了分析,并提出了在天津市科技型中小企业中应该实施以虚拟股权激励方式为主的股权激励模式的理论架构。     

中国明代与西方文艺复兴时期女性用物文化之异同

“裹足”与“箍腰”分别是中国明代与西方文艺复兴时期最为风行的时尚行为。由此中国风靡“三寸金莲”,而西方出现了“塑身内衣”,虽然给女性的肉体上带来很大的痛苦却极为流行。本文通过对这两种设计文化的分析开始,着意于引出其流行背后的原因,并对中国明代与西方文艺复兴时期女性审美、女性社会地位、女性用物发展趋向等方面的异同进行比较。     

A REVIEW OF SYSTEMS COINTEGRATION TESTS

The literature on systems cointegration tests is reviewed and the various sets of assumptions for the asymptotic validity of the tests are compared within a general unifying framework. The comparison includes likelihood ratio tests, Lagrange multiplier and Wald type tests, lag augmentation tests, tests based on canonical correlations, the Stock-Watson tests and Bierens' nonparametric tests. Asymptotic results regarding the power of these tests and previous small sample simulation studies are discussed. Further issues and proposals in the context of systems cointegration tests are also considered briefly. New simulations are presented to compare the tests under uniform conditions. Special emphasis is given to the sensitivity of the test performance with respect to the trending properties of the DGP.     

Alternative rates of structural change in Norwegian dairy farming: impacts on costs of production and rural employment

The economies of size in Norwegian dairy farming are far from exploited. There is increasing pressure on cost savings through faster farm restructuring. Such a structural transition could have severe effects on other concerns (rural employment and social well being, landscape preservation, biodiversity, heritage values, etc.) valued by the society. A simulation model is developed to study effects of alternative rates of structural change on the social costs of milk production, farm employment and farm subsidies. The model is based on economic conditions at the farm level for various size groups and regions. Changes in the model's farm structure depend on the exit rate of existing farms in various size groups and the size of newly established farms. When new farms are substituted for existing farms, a rapid change in farm structure and a new herd size of 60 cows (the largest evaluated) results in the lowest costs. Approximately 60% of the cost savings achieved by larger farms can be attributed to lower labour input, resulting in considerable losses of employment. Job losses will have the greatest negative family and community impacts in areas located far from urban centres, because a large share of the milk is produced is such areas, farms are smaller and there are fewer non-farm employment opportunities. Government support is necessary to preserve small farms’ provision of multiple benefits. The balance between cost-saving pressures and the rationales for retaining small farms under increasingly liberalized market regimes is bound to be a complex issue.     

中小企业在创新过程中应遵循的基本策略

文章认为 ,注重创新是保障中小企业生存和发展的必然选择。为了使创新活动达到预期的效果 ,中小企业的经营者应该抓住产品创新、市场创新、管理创新这 3个关键点 ,坚持顾客导向和动态联盟这 2项指导原则 ,遵循 1个系统的创新工作程序     

山岳派、雅各宾派与雅各宾主义

山岳派没有被认可的共同纲领。雅各宾派作为山岳派的主导派别 ,二者在重大事件上几乎是同义的。在从 1792年底开始的第三代人领导期间 ,很多雅各宾派成员在大革命中提高了经济地位 ,成了不同于贵族和人民的“自觉的资产者”。雅各宾主义是启蒙运动中自然法和理性主义哲学的继续和发展 ,曾给予大革命最进步的内容。     

本土叙事：高云览《小城春秋》的地域特色

高云览《小城春秋》受读者喜爱的原因在于作者采取一种带有厦门味的＂小城书写＂方式,关注小城厦门的地域文化传统,主张向民间文化学习,并用来作为政治斗争的武器。但是,当小城文化传统成为革命者新思想的阻力时,作者又采取了一种批判态度,体现其除旧布新的思想文化改造倾向。