对林业税费的经济学分析

该文运用经济学的基本工具———供给和需求曲线 ,以商品林为研究对象 ,探讨了林业税费的作用机理和内涵。该文认为商品林生产具有正的外部性 ,市场失灵使生产者将不能提供社会真正所需要的商品林数量。在封闭的市场条件下 ,林业税费会直接成为价格的一部分 ,商品林生产者应当能够获得正常利润 ,与税费高低无关 ,但会使一部分林地退出生产。林业补贴是一种负的林业税收。在开放市场经济条件下 ,国内商品林供应量低于没有林业税收时的商品林供应量 ,更低于考虑社会生态需求时的商品林供应量 ,造成巨大的社会福利损失 ,应减免林业税费、增加林业扶持、取消价格管制。该文进一步研究了与林业税费密切相关的森林采伐限额政策 ,认为对商品林应该完全取消采伐限额政策     

Comparing the effectiveness of respondent-driven sampling and quota sampling in migration research

We evaluate the effectiveness in empirical migration research of the respondent-driven sampling (RDS) and the quota sampling with regard to four criteria: quality of the data; sociometric diversity of the sample; geographic coverage of the sample; and cost-effectiveness. We review two surveys of ex-USSR migrants, conducted simultaneously in the Warsaw metropolitan area, each undertaken with the use of one of the two sampling methods. We find that although the RDS was considerably costlier, it enabled faster data collection and posed a lower risk of underestimating the cost of the survey. We also find that the RDS generated higher-quality data, and that it was more successful in surveying short-term circular migrants. This comparative evaluation contributes to the literature on social research methods in that it links the sampling methods with the quality and character of the data, and helps assess the usefulness and applicability of RDS in empirical migration studies.     

A Bayesian model for multiple change point to extremes,with application to environmental and financial data

Abrupt changes often occur for environmental and financial time series. Most often, these changes are due to human intervention. Change point analysis is a statistical tool used to analyze sudden changes in observations along the time series. In this paper, we propose a Bayesian model for extreme values for environmental and economic datasets that present a typical change point behavior. The model proposed in this paper addresses the situation in which more than one change point can occur in a time series. By analyzing maxima, the distribution of each regime is a generalized extreme value distribution. In this model, the change points are unknown and considered parameters to be estimated. Simulations of extremes with two change points showed that the proposed algorithm can recover the true values of the parameters, in addition to detecting the true change points in different configurations. Also, the number of change points was a problem to be considered, and the Bayesian estimation can correctly identify the correct number of change points for each application. Environmental and financial data were analyzed and results showed the importance of considering the change point in the data and revealed that this change of regime brought about an increase in the return levels, increasing the number of floods in cities around the rivers. Stock market levels showed the necessity of a model with three different regimes.     

关于中美经贸摩擦两个问题的探讨

随着中美经贸关系的日益发展,也推动了两国的经济发展,但其中也不时出现一些分歧和摩擦。诸多因素推动和影响着中美经贸关系的发展;两国的共同利益、经济的互补性、中国坚定不移的对外开放政策和美国对中国市场的需求是双边经贸迅速发展的基础。对于两国间存在着一些典型性的贸易摩擦问题,我们应该积极探讨解决的办法。     

我国碳强度减排的实施路径研究

我国碳排放区域格局与区域经济发展的关系已引起学者关注,并取得了部分研究成果。在人均碳排放原则与2020年各省的碳排放配额预测数据基础上,根据我国区域经济发展不均衡和碳排放量不均等的现实,国家应在区域间建立碳强度减排机制和碳减排项目合作机制。这不仅有利于缩小东、中、西三大区域间的差距,实现公平目的,还能更迅速有效地实现我国碳强度减排目标。     

信贷规模与房地产价格的非线性动态关系——基于中国直辖市数据的比较研究

运用非线性平滑转换模型对中国直辖市的信贷规模与房地产价格的动态关系进行对比研究。研究发现如果想要通过控制信贷规模调控房地产价格,天津和重庆更容易达成调控目标,北京则很难。在信贷规模对房地产价格产生非线性影响的条件下,信贷规模对房地产价格的影响存在不同状态,重庆在不同状态间的变化速度最快,其次是天津,最慢的是北京。     

论《中美农业合作协议》对湖南农业发展的影响

《中美农业合作协议》及美方要价对湖南农业来说可谓是挑战与机遇并存 ,风险与希望同在。因此 ,湖南应充分利用四年的缓冲期 ,积极采取应对措施 ,趋利避害 ,以取得成功     

On the emptiness of the stability set of order d

We know from Li's theorem (1993) that the stability set of order d may be empty for some preference profiles. However, one may wonder whether such situations are just rare oddities or not. In this paper, we partially answer this question by considering the restrictive case where the number of alternatives is the smallest compatible with an empty stability set. More precisely, we provide an upper bound on the probability for having an empty stability set of order d for the majority game under the Impartial Weak Ordering Culture assumption. This upper bound is already extremely low for small population and tends to zero as the number of individuals goes to infinity.     

构建失业预警系统的探索

建立失业预警系统,为政府有效控制失业率、进行劳动力市场宏观调控提供可靠的参考依据。失业预警系统主要包括预警方法、预警指标、制度安排和管理信息系统等几个方面。为了控制失业率,政府应加强对失业的预测;政府应把控制失业率作为宏观调控的主要目标;建立专职失业风险监测机构;改进失业和就业的统计口径,加强就业统计。     

浅析我国纺织品贸易存在的主要问题

纺织业至今仍然是我国制造业的骨干,是带动经济增长的主要力量之一,在我国28个制造业部门中,2003年至今它的各项指标均处于领先地位。随着我国市场的逐步开放、全球经济一体化进程的不断加快,使得国际、国内市场对纺织品服装的需求不断增加,为我国纺织业提供了更广阔的的发展空