畜牧产业结构变动对我国粮食安全的影响分析

［目的］改革开放40多年来，我国畜牧产业结构不断调整和优化，其生产供给结构与消费需求结构的变动与我国粮食安全问题息息相关。［方法］文章基于改革开放40多年来畜牧产业发展历程，从供给与需求两个维度分析我国畜牧产业结构变动的特征，并进一步探究畜牧产业结构变动与我国粮食安全间的作用机理，最后运用灰色关联度分析法实证其关联影响度。［结果］我国畜牧产业结构由耗粮型为主向节粮型转变，畜产品供给结构趋于合理，但不同区域间存在较大差异； 我国居民对畜产品消费需求量增加，但城乡居民畜产品消费结构及变动存在一定差异性； 畜牧产业结构变动与粮食安全有重要联系，畜牧业发展同保障国家粮食安全并不矛盾，畜牧产业结构变动主要通过耕地、基于口粮替代的食物需求结构变化及饲料粮需求3个方面作用于粮食安全； 具体来看，粮食播种面积、耗粮型畜产品比重和耗粮型畜产品饲料转化率对粮食安全水平的关联影响较大，节粮型畜产品比重与节粮型畜产品饲料转化率对粮食安全水平的关联影响小于耗粮型畜产品的影响。［结论］不断提高不同畜产品的饲料转化率，加大非粮型饲料资源开发利用度，推广非粮饲料应用技术，加快畜牧产业转型升级，满足消费者需求和保障国家粮食安全。     

中国农村减贫成效测度、分解及影响因素研究——基于分布动态学框架的CFPS数据分析

测算农村减贫成效并考察减贫成效的影响因素对我国打赢"脱贫攻坚战"具有重要的现实意义。本文基于覆盖我国东、中、西和东北四大地区的CFPS调查数据,在Quah(1997)的分布动态学(Distribution dynamics)基础上构建了完整的减贫成效分析框架。首先测算出各地区农村家庭贫困内部状态的Markov转移概率矩阵,并在此基础上构建了可分解的绝对、相对减贫指数,以综合考察各地区的农村减贫成效,随后本文通过首次构造的"条件Markov模型"进一步考察了减贫成效的影响因素。研究结果发现:(1)样本考察期内,我国各地区的农村贫困状况随着时间的积累逐渐变好,贫困发生率均有所下降;(2)减贫过程中仍存在着脱贫又返贫的现象,农村家庭的深度贫困固化问题比轻度贫困问题更加严重,意味着扶贫开发工作正式进入攻坚时期,扶贫难度加大;(3)家庭成年成员特征、家庭特征以及收入类型对农村减贫成效的影响显著性情况存在着时段和区域的异质性。其中,家庭成年成员受教育水平、家庭中是否有成员从事有薪酬的农业劳动、工资性和营业性收入对家庭的贫困状态变动具有更显著的影响。基于此,政府应贯彻落实精准扶贫,将扶贫重点放在中西部地区和处于深度贫困的家庭,另外应再调整和倾斜扶贫资源与扶贫政策,将提高农民受教育水平、增加非农业就业机会作为主要减贫途径,将促进农村工资性和营业性收入增长作为主要的政策倾斜方向。     

Financial crises,debt overhang,and firm growth in transition economies

ABSTRACT

We examine the effects of the global financial crisis of 2008 and the European debt crisis of 2011 on the relationship between capital structure, investments, and performance for Eastern European companies. While the existing literature documents how firms’ investments are sensitive to the availability of internal funds and to debt holdings, we further investigate whether this investment sensitivity also translates in different levels of performance, and document that capital structure indeed has both a direct and an indirect effect, mediated by the capital expenditure channel. We show that firms with higher financial flexibility experience higher investments and returns on capital. Over-levered firms instead suffer from a debt overhang condition, forcing them to curb investments, and consequently experiencing lower performance. Overall, we provide evidence on the importance of capital structure and financial flexibility on investments and performance, showing the real consequences of the debt overhang condition on firm value creation. Firms should therefore aim at maintaining adequate financial flexibility in order to be able to pursue future profitable investment opportunities, and avoid the under-investment problem arising from a debt overhang situation.     

Maximizing political vote in multiple districts

This paper models a resource allocation problem in the political context. Voters and political candidates of two parties are positioned in each of n given electoral districts. We assume that each voter will vote for the candidate he is more attracted to. This attraction is modeled by an attraction function. Each of the parties now attempts to allocate a finite budget to maximize their objective, which is either the popular vote or the number of districts, in which the party has a majority. Individual scenarios are examined with respect to leader-follower solutions and Nash equilibria. The paper then describes a dynamic model that successively allocates existing funds plus additional donations to candidates in different electoral districts.     

中美贸易战的危害与对策

分析中美国情现状,对中美经济状况进行对比,对美国发动贸易战的原因进行分析:美国对华贸易逆差过大;美方认为中方侵犯美国企业知识产权,中国的重商主义对美国经济产生了致命影响;转嫁国内矛盾,战略遏制中国。分析美国发动贸易战的危害,提出了中国应对挑战应妥善应对短期冲击,对等还击;拉动内需,加快自身经济结构调整等对策。     

城镇群空间结构与要素集聚

依据城镇化发展过程中要素空间集聚理论，展开区域经济发展的空间经济结构研究。通过城市引力、克鲁格曼指数计算，比较分析城镇群内部城市吸引力和城市产业分布的差异性，通过人口与生产空间分布集中度指标和不一致系数的测算，分析了山西省城镇群空间要素集聚效应。研究表明，山西省的城镇群规划与要素空间集聚趋势整体一致，城市间产业分工体系基本形成，城镇群的要素集聚效应明显，但人口与生产分布仍存在不一致性。研究认为，山西省城镇群发展应该继续明确各城市的产业分工和特色，引导劳动力和资本要素的合理流动，实现人口与生产空间分布的一致。     

东北地区产业升级的困境与出路

产业结构的优化升级对于推动区域经济协调发展具有重要意义。目前，东北地区的产业发展仍未摆脱结构不合理、布局趋同、国有资产负债重、企业竞争力不强的困境。制约产业结构优化升级的因素在于思想观念保守、产业融合度低和制度环境不佳。需要突破某些认识误区、优化政策环境、发展替代和后续产业。     

人口结构与地方政府义务教育公共支出——基于中国省级面板数据的研究

利用我国2007-2011年间31个省市地区的平衡面板数据,从供给和需求两方面出发实证分析我国义务教育公共服务支出影响因素。在影响供给的因素讨论中,考察了财政收入、财政分权程度、转移支付、政府竞争力等因素。在影响需求的因素讨论中,探讨了人口自然与非自然结构,人口家庭结构对义务教育公共服务需求的影响。最后将我国分为东部、中部、西部三个地区,进一步剖析我国义务教育公共服务支出影响因素的区际差异。     

产业融合发展、农产品供需结构与农业供给侧改革核心探寻

在农产品价格保护制度背景下,不能完成产业融合会限制产业之间的关联效应发挥,导致农产品供需反馈机制瓦解,从而使农产品供需结构出现矛盾。因此,需要对产业融合发展、农产品供需结构以及农业供给侧改革核心进行研究。论文从产业融合发展的必要性、产业融合发展与农产品供需结构之间的形成机理出发进行分析,探讨在新形势下,产业融合发展与农业供给侧改革的选择策略,从而创新我国的农业经营体系,构建完善的农业社会化服务体系,推动我国农业供给侧结构性改革的进一步发展。     

Moral hazard,debt overhang and capital structure

This paper investigates the impact of managerial moral hazard on the debt overhang of a firm by constructing a contingent claims model in which the manager faces costly effort. Using a calibrated capital structure model, we show that the costs of debt overhang become more serious in the presence of managerial moral hazard. Such costs even account for more than half of the total agency costs at a high level of cash flow. Moreover, in contrast to the results of Hackbarth and Mauer (2012), our model predicts a U-shaped relationship between the leverage ratio and investment opportunities of a firm, which is caused by managers’ moral hazard. Finally, by considering this moral hazard, we also show the coexistence of low leverage ratios and high credit spreads, which explains the phenomenon of “low debt levels and high credit spreads” observed in practice.