我国大米产业波动的来源及冲击路径

通过采用修正后的两变量结构向量自回归模型考察我国大米产业波动来源,并利用脉冲响应函数分析供求冲击对大米价格和产出的传导路径。结果发现:大米产业70%的价格波动来源于供给冲击的作用;短期内供给冲击占据产出波动的主导地位,而长期内需求冲击解释54%左右的价格波动;总体而言,供给冲击在中国大米价格波动中具有主导作用。因此,政府应对大米产业波动及时调控,防止由于政策调控的滞后效应,导致价格与产出波动放大的结果。     

经济增长的需求动力结构调整研究述评

经济增长的需求动力结构调整是转变一国经济增长方式的重要体现。20世纪80年代以来,我国学者对该领域问题进行了持续关注和研究。通过对中国经济增长的需求动力结构现状及演变、需求动力结构对经济发展影响、需求动力结构合理性评估、需求动力结构调整的目标方向、需求动力结构调整理论与经验依据、需求动力结构变动影响因素及失衡原因、需求动力结构调整对策等方面的文献进行回顾、梳理和归纳,并进行简要评述,为后续开展系统深入研究奠定基础。     

农村社区自我供给公共服务条件下的农民需求表达机制分析

在当前中国,面对人数众多、高度分散、需求多元化的农民,农村社区要想有效地提供农村公共服务,必须解决农民需求表达的难题。用手投票和用脚投票是比较常见的两种需求表达机制。通过对社区自我供给公共服务条件下上述两类机制的适用性的分析,提出相关政策建议。     

冲击型负荷下的生产存储模型研究

建立了考虑冲击需求、变化生产率的最优生产存储库存策略. 其特点是:把一个生产周 期分为多个生产阶段,各个生产阶段时间可以不同;在每个生产阶段中,允许生产率小于需求 率,允许提前生产;而且,最大生产率要小于最大需求率. 研究发现,为满足冲击需求,提前存储 较多而启动机器数量较少,或提前存储较少而启动机器数量较多,不一定能够取得最佳效益, 要根据存储费用和启动费用共同确定. 在有限生产率的条件下,得出一种寻求最优生产- 库存 策略,为此类库存系统的管理决策提供了理论依据.     

铁路信息共享需求分析

铁路信息共享需求分析是整合利用铁路信息、实现铁路信息充分共享的必经途径.本文通过对铁路信息的层次、分布和流向进行分析建立了铁路信息管理模型,并在此基础上从铁路内部、铁路内外和决策支持三个方面构建了铁路信息共享需求分布模型,最后从体制、标准、测评和统计等方面就铁路信息共享的实施提出了几点建议.     

Sequential and Simultaneous Decision Making for Optimizing Health Care Resource Flexibilities

Health care administrators commonly employ two types of resource flexibilities (demand upgrades and staffing flexibility) to efficiently coordinate two critical internal resources, nursing staff and beds, and an external resource (contract nurses) to satisfy stochastic patient demand. Under demand upgrades, when beds are unavailable for patients in a less acute unit, patients are upgraded to a more acute unit if space is available in that unit. Under staffing flexibility, nurses cross‐trained to work in more than one unit are used in addition to dedicated and contract nurses. Resource decisions (beds and staffing) can be made at a single point in time (simultaneous decision making) or at different points in time (sequential decision making). In this article, we address the following questions: for each flexibility configuration, under sequential and simultaneous decision making, what is the optimal resource level required to meet stochastic demand at minimum cost? Is one type of flexibility (e.g., demand upgrades) better than the other type of flexibility (e.g., staffing flexibility)? We use two‐stage stochastic programming to find optimal resource levels for two nonhomogeneous hospital units that face stochastic demand following a continuous, general distribution. We conduct a full‐factorial numerical experiment and find that the benefit of using staffing flexibility on average is greater than the benefit of using demand upgrades. However, the two types of flexibilities have a positive interaction effect and they complement each other. The type of flexibility and decision timing has an independent effect on system performance (capacity and staffing costs). The benefits of cross‐training can be largely realized even if beds and staffing levels have been determined prior to the establishment of a cross‐training initiative.     

Inventory Management for Customers with Alternative Lead Times

It is common for suppliers operating in batch‐production mode to deal with patient and impatient customers. This paper considers inventory models in which a supplier provides alternative lead times to its customers: a short or a long lead time. Orders from patient customers can be taken by the supplier and included in the next production cycle, while orders from impatient customers have to be satisfied from the on‐hand inventory. We denote the action to commit one unit of on‐hand inventory to patient or impatient customers as the inventory‐commitment decision, and the initial inventory stocking as the inventory‐replenishment decision. We first characterize the optimal inventory‐commitment policy as a threshold type, and then prove that the optimal inventory‐replenishment policy is a base‐stock type. Then, we extend our analysis to models to consider cases of a multi‐cycle setting, a supply‐capacity constraint, and the on‐line charged inventory‐holding cost. We also evaluate and compare the performances of the optimal inventory‐commitment policy and the inventory‐rationing policy. Finally, to further investigate the benefits and pitfalls of introducing an alternative lead‐time choice, we use the customer‐choice model to study the demand gains and losses, known as demand‐induction and demand‐cannibalization effects, respectively.     

基于供求关系的房价波动分析

基于1999—2017年中国35个大中城市的面板数据,构建基于供求关系的面板回归模型,从国家和区域两个层面对造成房价波动的原因进行探究。结果表明:价格预期在全国和区域模型中均对房价有显著的正向影响,且在大多数地区,其影响力大于其他因素;人口对房价有正向影响,但只在北部沿海、东部沿海和南部沿海显著;收入对南部沿海、黄河中游和西南地区的房价均有显著的正向影响,而在北部沿海、东部沿海、长江中游、西北地区和东北地区,该因素对房价的影响并不显著;除全国和西南、西北地区外,房屋造价作为成本因素对绝大多数地区的房价有正向影响;信贷的可获得性作为政策因素对房价有正向影响,除南部沿海和黄河中游外,在其他区域均显著;住宅开发投资与住宅价格呈负相关关系,但其只在少数经济发达地区显著。因此,未来对房地产市场的调控应根据区域房价波动影响因素的不同区别对待,因地制宜。     

借贷能力、风险收益与新型农业经营主体经营效率

通过构建一个新型农业经营主体与金融组织讨价还价的理论模型,在纳什议价均衡的基础上分析新型经营主体最优产出水平与其借贷能力、风险收益的关系。基于中国12省的微观调查数据,采用双边随机边界检验,对理论模型进行了实证研究,结果表明：借贷能力不足是新型经营主体经营无效率的主导因素,最终使平均净效率下降了8.13%;正规金融机构和民间借贷均对新型经营主体的经营效率有显著影响,并且民间借贷对经营效率的影响更强;新型经营主体的负责人能力、盈利能力、组织化程度等,与其经营效率呈正相关关系。提出应通过金融体系创新、完善民间借贷法规等途径,降低新型农业经营主体的融资约束,提高其负责人的经营水平,加强新型经营主体的组织化程度。     

大数据时代理论供给:现实困境、战略对策与有效治理

大数据时代理论供给是指借助大数据信息与技术,把人民需要的科学理论快速有效输送到人民的理论需求端。大数据时代,理论主体层次不齐、现实问题层出不穷、供给渠道纵横交错、供给体系缺乏统一等造成一定程度的理论供给现实困境。运用大数据思维与技术,准确把握理论需求信息、着力打造理论供给侧和全面创新理论传输媒介系统是构建大数据时代理论供给的战略对策。实现大数据时代理论供给的有效治理,关键要坚持以人民为中心的治理理念,坚持依法治理的战略选择,坚持价值治理和技术治理有机统一的原则。