Mixed farming in Africa: the search for order, the search for sustainability

This paper examines the interest in the development and promotion of mixed farming in sub-Saharan Africa. For over 70 years mixed farming has been a dominant model for agricultural development despite the limited success of many of the programmes which have specifically promoted it. It is suggested that the establishment of mixed farming as a strong development theme is related to its promise to address a range of environmental and social concerns, and in so doing, help create order out of a ‘chaotic’ African countryside. Mixed farming is again being highlighted with the more recent interest in sustainable, environmentally friendly agricultural systems. However, there is considerable evidence that African farmers have adopted a flexible principles-based approach to the use of component technologies commonly associated with the mixed farming model. This must be fully acknowledged, and the seduction of unitary models avoided, if agricultural research is to contribute efficiently to the development of more sustainable farming systems.     

新时代混合所有制改革的目标、推进速度与模式探索——基于契约视角和中外历史及现实经验的思考

改革开放后,混合所有制改革在党的文件中已有20多年的酝酿和发展;党的十八届三中全会后,各级政府积极采取行动推动这个改革。然而,在企业层面,交易属性和交易成本决定了混合所有制改革难以大规模快速推进;在国家层面,混合所有制改革不是私有化,而是要在多种所有制经济“共赢同进”中完善社会主义基本经济制度,做强做优做大公有制经济。新时代的混合所有制改革应当是渐进式的、稳健的,而不是运动式的,更不是激进的私有化;混合所有制改革的模式应是多样化的,要积极探索真正体现初心的、适宜的改革模式。     

国有资本参股会影响民营企业的内部控制质量吗

混合所有制改革是进一步巩固和完善社会主义基本经济制度的重要举措,在推动经营机制转换、优化市场资源配置、提升企业运营效率等方面取得了显著成效。但是现有关于混合所有制改革经济后果的研究多集中在“正向混改”领域,而“反向混改”领域的研究相对较少,且对于民营企业内部治理机制缺乏深入系统的分析。为此,文章以2003-2021 年A 股上市公司为样本,研究国有资本的加入对民营企业内部控制质量产生的影响。研究发现：首先,国有资本参股能够通过提高民营企业的治理水平、增加媒体关注度、缓解民营企业的融资约束从而显著提升民营企业的内部控制质量。其次,进一步分析表明,国有资本参股的积极作用在有政治关联的企业和非家族企业更为显著;同时对于国资主体而言,其正面作用在地方国有企业及内部控制质量高的国有企业中更为明显。最后,本文发现,国有企业参股在内部控制战略、经营、报告、合规等层面均发挥一定积极作用,从而促进了民营企业内部控制整体质量提升。文章的发现丰富了“反向混改”经济后果以及企业内部控制质量影响因素的相关文献,为深化混合所有制改革提供了新的理论支撑和经验证据。     

Media effects on sustainable food consumption. How newspaper coverage relates to supermarket expenditures

Information provision is often considered to have an important role to play in changing consumers' choices. However, there is still no consensus on the mechanisms by which information might influence specific consumer expenditures, especially in relation to environmentally friendly food products. This paper explores whether the public debate on sustainable consumption in UK broadsheets and tabloids relates to observed consumers' expenditures. It does so by relating the number of published articles on selected sustainability topics to consumers' food expenditure in a leading UK supermarket from May 2009 to May 2011, using regression analysis. We selected only regular supermarket's shoppers who frequently buy the Sunday editions of the analyzed newspapers. Results indicate very sparse and inconsistent correlations suggesting that the impact of information is only minimally effective. The number of newspaper articles relates mainly to expenditures on organic, wholegrain and low salt products, possibly indicating a preference for healthy food. No consistent effects are observed when media target a change in more general food categories (e.g. a reduction in food of animal origin), although we observed some influence on purchases of fish. Finally, results indicate some correlations with purchases of meat for the readers of the Telegraph. In order to contextualize some of the results, we applied content analysis to a subsample of published articles on organic food. The qualitative approach shows that the framing of the news is important: change is positively related to information proposed uncritically; and negatively to information contextualized as a highly structured debate.     

考虑物料、产能和客户优先级三重约束的订单允诺管理问题研究

客户订单允诺管理是在市场全球化的背景下．综合考虑各种资源有限性,对客户的订单给予准确的答复．因而具有很好的应用前号。文章对现有客户订单允诺模型做出改进,在供应链资源即物料和产能双重限制下,加入客户优先级约束,通过建立模型求解,给出合理的客户订单允诺机制。文中不仅定性分析客户优先级．而且将客户优先级量化为客户价值来表示,使该订单允诺管理机制更为有效．更有利于企业的长期可持续发展。     

我国金融混业经营的监管问题研究

随着金融竞争的加剧、金融需求的变化和信息技术的发展,混业经营已成为我国金融业发展的必然趋势。本文以我国金融混业经营的背景和现状为出发点,在分析我国金融混业经营监管困境的基础上,有针对性地提出我国金融混业经营的监管对策。     

基于混合集合规划的多场景应急设施选址优化

多场景应急设施选址问题具有约束复杂、时效性强、规划周期短等特点。以混合集合规划为算法框架的自然约束语言NCL能对该问题进行建模与求解。以一个典型多场景应急设施选址问题为例,证明了NCL可有效求解该类问题。     

混合寡头竞争、污染物排放与环境税

通过建立一个混合双寡头市场竞争模型,借以考察在国家征收环境税的条件下,国有企业的私有化程度对污染物排放、社会福利以及环境税率的影响。研究表明:当国有企业的私有化程度较低时,继续私有化将会导致污染物排放的增加和社会福利的增加;当国有企业的私有化程度较高时,继续私有化将会导致污染物排放的降低和社会福利的下降;同时,环境税则随着国有企业私有化程度的提高,始终保持下降趋势。     

基于混合多项式模型的韶山红色旅游需求人数预测

基于三次和四次多项式拟合模型。针对韶山红色旅游景区旅游需求人数预测问题,提出了混合多项式拟合预测模型．该模型可以解决信息呈递增趋势的问题,结果具有一定的可信度．将该模型与灰色预测模型GM（1,1）进行比较,结果表明,混合多项式拟合预测模型的平均相对误差明显要低于GM（1,1）模型,且计算代价更小．     

所有权和市场绩效的理论逻辑与经验证据——比较视角及去意识形态化反思

本文通过对新古典经济学、契约理论等理论的最新反思,并根据新比较经济学、新规制理论、混合寡占模型等理论分析与经验研究的最新进展,为所有权与市场绩效关系提供了更深刻细致的见解。以往关于所有权与市场绩效的研究深受特定政治偏好与制度约束的影响,很多研究存在系统性缺陷,结果常常缺乏稳健性。当代研究更加注重“去意识形态化”的科学态度和模型设置背后的知识假定,现有的理论与计量分析工具只能证明国家所有权与私人所有权互有优劣,相关研究必须避免外生假定一种所有制结构的优越性,这样才能重新开辟出一片更为广阔的领域。