当前经济形势与互换利率走势判断

2010年上半年,利率互换市场交投活跃。随着市场对经济增长和政策运用预期的不断修正,互换利率继1月创出新高后一路振荡下行。预计下半年,在基本面、政策面、资金面和利率自身波动节奏的相互作用下,市场参与者的预期将反复进行修正,互换利率将呈现宽幅震荡。     

Structural transformation or elite land capture? The growth of “emergent” farmers in Zambia

Over the last decade, Zambia has witnessed a rapid increase in the number of medium-scale “emergent farms” cultivating 5–20 ha of land. This study analyzes the factors underpinning this growth. We find that the growth of emergent farmers in Zambia is primarily attributable to land acquisition by salaried urbanites and by relatively privileged rural individuals. We found little evidence to support the hypothesis that the rise of emergent farmers primarily represents a process of successful accumulation by farmers who began farming with less than 5 ha of land, a situation faced by more than 95% of farming households. We argue that these outcomes are the result of Zambia’s land administration and agricultural spending policies. Rising concentration of landholdings in Zambia raises serious questions about the potential of current agricultural growth to act as a vehicle for broad based economic growth and poverty reduction.     

Land pressures,the evolution of farming systems,and development strategies in Africa: A synthesis

Evidence assembled in this special issue of Food Policy shows that rising rural population densities in parts of Africa are profoundly affecting farming systems and the region’s economies in ways that are underappreciated in current discourse on African development issues. This study synthesizes how people, markets and governments are responding to rising land pressures in Africa, drawing on key findings from the various contributions in this special issue. The papers herein revisit the issue of Boserupian agricultural intensification as an important response to land constraints, but they also go further than Boserup and her followers to explore broader responses to land constraints, including non-farm diversification, migration, and reduced fertility rates. Agricultural and rural development strategies in the region will need to more fully anticipate the implications of Africa’s rapidly changing land and demographic situation, and the immense challenges that mounting land pressures pose in the context of current evidence of unsustainable agricultural intensification, a rapidly rising labor force associated with the region’s current demographic conditions, and limited nonfarm job creation. These challenges are manageable but will require explicit policy actions to address the unique development challenges in densely populated rural areas.     

The effect of government 5G policies on telecommunication operators’ firm value: Evidence from China

To lead the world's fifth-generation mobile communication networks (5G) market, China introduced several policies to support 5G industry development that will impact telecommunication operators, the main implementers in this industry. Thus, this study examines the impact of the government's 5G policy announcements on telecommunication operators' firm value in China, where the state exerts a strong influence on industry development. We find that government policy announcement in general affects telecommunication operators' stock returns negatively, and when the government announces policies with a higher level of interference, the decline in firm value is more pronounced. To understand the comprehensive impact of 5G technology on telecommunication operators, we also examine the effect of institution-driven corporate technology R&D and investment activities on firm value. We find that the firms' 5G activities also decrease their firm value, and this effect is more significant than government policy announcements. These results imply that the market has a negative evaluation of the introduction of 5G technology due to its immaturity and uncertainty. This study provides a basis for understanding the market's views on 5G technology and development policies.     

Internet of things and the economics of 5G-based local industrial networks

Fifth generation (5G) networks raise governance and management challenges that did not exist in 3G and 4G wireless technologies. Advanced wireless functionality enables new applications and services based on smart, physical, network infrastructures, many of them expected to be localized. As a general-purpose technology, 5G can be configured in numerous ways to support innovative applications across many sectors. Smart network applications and services must integrate physical and virtual components in innovative ways. In addition, general capabilities of 5G must be combined with complementary technologies, such as big data analytics and edge cloud services, to create services for specific use cases. Varying throughput and latency requirements of distinct use cases require differentiated technical solutions. Appropriate frequencies must be aligned efficiently with other features within the footprint of particular, local industrial networks. National policy makers, suppliers, and users are responding differently to these governance and management challenges. These approaches balance differently the trade-offs between experimentation, differentiation, and harmonization. Comparative analysis can inform gradual improvements of the governance of 5G-based, local industrial networks.     

Is Netflix a threat to the cable TV industry? Evidence from Brazil

In recent years, the Brazilian cable TV industry has experienced a sharp downturn. In parallel, the over-the-top platform Netflix gained popularity and Brazil has become one of its biggest markets. The objective of this paper is to investigate the competitive effects of Netflix's entry on the incumbent cable TV industry. We explore the regional variability of Netflix's popularity (measured by Google Trends) and combined this information with official data of the cable TV market. Using a two-way fixed effects estimator with state-month observations (covering the period of 2012–2019), we showed that the increase in one standard deviation in Netflix popularity is associated with a 3.62% reduction in the density of cable TV subscribers and with a 19.69% reduction in the number of small firms that operate cable TV.     

空间视角下R&D投入对区域创新能力的影响研究——基于科技政策组合的调节作用

基于知识生产函数模型和创新地理学理论,本文利用我国30个省(区、市)2008~2020年的面板数据,通过空间计量模型实证分析R&D投入对区域创新能力的影响及空间溢出效应,并从政策目标与政策工具的耦合协调性视角理解科技政策组合,分析科技政策组合的调节效应。研究发现,我国省域创新能力呈现由东向西逐渐减弱的“梯形”分布特征;R&D资金和R&D人员对于本地区域创新能力提升具有显著的正向影响,但空间溢出效应均不显著;科技政策组合正向调节R&D投入对区域创新能力的促进作用。对此,国家应制定适宜的区域创新战略,地方政府应探索差异化创新驱动发展路径并提升科技政策组合的耦合协调性。     

基于MA2IDDPG算法的异构多无人机协同突防方法

为了形成智能化异构多无人机协同突防策略,提出了基于多智能体异步模仿深度确定性策略梯度算法的异构多无人机协同突防方法。首先,基于典型DDPG方法,采用异步并行框架进行改进,提高经验的收集效率。其次,分别构建基于专家经验知识的牵引性奖赏函数和基于任务结果的描述性奖赏函数。再次,通过分阶段训练后,使得深度神经网络产生的协同突防策略能够快速达到专家经验知识水平后,进一步提高对抗水平。最后,在仿真实验中,构建了异构多无人机协同突防环境,对改进方法和典型DDPG方法的对抗效果进行了对比。实验结果表明,MA2IDDPG方法能够有效产生多无人机协同突防策略,并且在训练阶段表现更为稳定且对抗效果更优。所设计的创新性MA2IDDPG方法框架可有效应用于无人机群控制领域,特别是对异构无人机群的智能控制方法研究具有重要参考意义。     

基于PSM-DID模型的政策对试点企业经营绩效的影响评价研究——以供应链创新与应用试点政策为例

近年来,我国政府积极推进供应链领域政策的制定与发布,如何更好地评估既有政策带来的绩效成为政府进一步完善供应链相关政策的关键。本文选取商务部“供应链创新与应用试点”政策(商建函[2018]142号)作为研究对象,并构建双重差分倾向得分匹配(PSM-DID)模型,将试点企业经营绩效中的盈利能力指标ROA作为被解释变量,利用Stata15.0对2015~2019年5年间覆盖3494家样本企业的面板数据,共15278个样本进行处理计算,以此对该政策实施对试点企业经营绩效的影响效果进行评价。结果表明:2018年开始实施的供应链创新与应用试点政策,对试点企业的经营绩效ROA有着显著的正向促进作用。此外,企业规模、企业的资产负债率、托宾Q值和企业固定资产投资比率都对ROA有显著影响。其中企业规模和托宾Q值对ROA有正向影响,资产负债率和固定资产投资比率对ROA有负向影响。     

The involvement of utilities in the development of broadband infrastructure: A comparison of EU case studies

Energy companies and other utility providers have been often involved in the provision of telecommunications services. Nevertheless, their contribution to broadband development has varied significantly over time. In the late 1990s, both local and national utilities in the European Union (EU) engaged in the provision of broadband networks, but only few of them managed to establish themselves as major broadband providers. More recently, new projects involving national utilities have been announced in several EU countries, opening new scenarios for utilities’ contribution to Next Generation Access (NGA) development. This paper identifies and explores the factors affecting the entry and the success of utilities in the EU broadband market, through the comparison of four case studies from four EU countries (Germany, Italy, Sweden and the UK). The evolution of utility involvement in the EU broadband markets is assessed against the interaction of market, technology and policy factors, focusing on the impact of policy and regulatory measures. As a result, this paper provides fruitful insights into the relevance and effectiveness of public interventions in broadband markets. Across the four case studies, public support and public ownership emerged as the main drivers for the involvement of utilities in EU broadband markets, with regulatory measures and economies of scope exerting a limited and decreasing influence. However, the contribution of utilities has varied significantly across the cases studied, reflecting the different approaches taken at national and local level to support broadband development, in spite of the common regulatory framework.