创新要素投入产出效率随机变动测度与结果分析

创新要素配置在投入产出两个环节中生成大量不完全技术信息，投入产出效率随机变动更加明显。从投入产出数据集合中提炼共同因子，与不可观测变量构成预测器，建立因子增广向量自回归模型(FAVAR)，分析随机变动方差构成，测度投入产出效率随机变动程度。随机变动效应包括水平效应、稳定性效应和规模效应。投入产出效率自回归扰动项表示随机变动程度，将其细分为共同因子，计算预测器方差及其与投入产出效率的协方差。基于669家上市公司月度、季度、半年度和年度技术研发数据，比较分析投入产出效率随机变动程度及形成原因，引入脉冲响应法分析变量方差构成与变动特征，提出相关政策建议。     

Viewpoint: Regulating meat consumption to improve health,the environment and animal welfare

Meat consumption has increased significantly in the last 50 years. This trend raises various health and environmental issues, as well as moral concerns regarding farm animal welfare. In this paper, we discuss the regulation of meat consumption in developed countries. Specifically, we discuss possible justifications for this regulation in terms of environmental, health and animal welfare considerations, as well as the effect of fiscal, informational and behavioral regulatory instruments. Finally, we present a list of challenges that policy makers and food scholars may need to confront in the future.     

Farming systems and Conservation Agriculture: Technology,structures and agency in Malawi

Conservation Agriculture (CA) is advocated as an agricultural innovation that will improve smallholder famer resilience to future climate change. Under the conditions presented by the El Niño event of 2015/16, the implementation of CA was examined in southern Malawi at household, district and national institutional levels. Agricultural system constraints experienced by farming households are identified, and in response the technologies, structures and agency associated with CA are evaluated. The most significant constraints were linked to household health, with associated labour and monetary impacts, in addition to the availability of external inputs of fertiliser and improved seed varieties. Our findings show that such constraints are not adequately addressed through current agricultural system support structures, with the institutions surrounding CA (in both Government extension services and NGO agricultural projects) focusing attention predominantly at field level practice, rather than on broader system constraints such as education and health support systems. Limited capacity within local institutions undermines long term efforts to implement new technologies such as CA. It is vitally important that the flexibility of farmers to adapt new technologies in a locally-appropriate manner is not closed down through national and institutional aims to build consensus around narrow technical definitions of a climate-smart technology such as CA. To enable farmers to fully utilise CA programmes, interventions must take a more holistic, cross-sectoral approach, understanding and adapting to address locally experienced constraints. Building capacity within households to adopt new agricultural practices is critical, and integrating healthcare support into agricultural policy is a vital step towards increasing smallholder resilience to future climate change.     

Assessing the contribution of artisanal fisheries to food security: A bio-economic modeling approach

Artisanal fisheries are an important food source in many developing regions. Quantitative bio-economic models are needed that comprehensively assess artisanal fisheries’ contribution to food security. Our model combines standard resource economics theory with the literature on food systems. It explains impacts of environmental variations and market development on output, prices and ultimately food security. The application to the Senegalese purse-seine fishery reveals that total sector rents account for 2% of per capita yearly food expenditures for the coastal inhabitants. We examine the relative importance of main drivers and the vulnerability of different regions. Market development plays a crucial role: The resource is of far greater relevance for remote regions.     

Permit markets,carbon prices and the creation of innovation clusters

Innovation clusters combining public and private effort to develop breakthrough technologies promise greater technological advances to slow down climate change. We use a multi-country model with an emission trading system to examine whether and how international climate policy can incentivize countries to create such innovation clusters. We find that a minimal carbon price is needed to attract applied research firms, but countries may nevertheless fail to invest in complementary research infrastructure. We construct a mechanism that leads to innovation clusters when emissions targets are set before uncertainty surrounding technological developments is resolved. It is a combination of low permit endowments for the country with the lowest costs to build the needed infrastructure, compensation for this country by profits from permit trade, and maximal possible permit endowments for the remaining countries. We outline how the EU-ETS can be further refined according to this mechanism.     

Well-being effects of extreme weather events in the United States

The increase in weather and climate disasters in recent years has prompted an interest in analyzing their consequences and the mitigation and adaptation measures that can help minimize their potentially large impacts on individuals’ welfare. We match thirty-one billion-dollar disasters with individual survey data from the Behavioral Risk Factor Surveillance System to estimate the effect of extreme weather events on the subjective well-being of U.S. residents. Our results indicate that natural disasters have a negative and robust impact on subjective well-being in the affected communities, and that, on average, this impact peaks 6 months after the event, and then decays over time. We then investigate the attenuating impact of health care access, flood insurance, and governmental assistance programs and find a partial compensating role for risk-transfer and relief measures. We also find that stronger emotional and social support mitigates the negative impact of natural disasters.     

The ‘curse of dimensionality’ resolved: The effects of climate change and trade barriers in large dimensional modelling

Solving large scale optimisation problems over space and time quickly generates a computational impasse, termed the ‘curse of dimensionality’. This severely limits the practical use of economic models, especially for determining the effects of climate change and protectionist trade policies. In this paper, we employ an innovative approach to solving (otherwise unsolvable) large scale systems through the use of parallel processing methods and a proper ordering of variables and equations in a ‘Nested Doubly Bordered Block Diagonal’ form. We illustrate how the approach can be used to solve an intertemporal CGE model with more than 500 million equations. Using existing damage functions, the framework allows us to determine the impact of climate change on long-run economic growth for 112 countries as a result of the effect of sea-level rise on land endowments, variation in crop yields and productivity and shifts in the demand for energy and transportation. We also compare our solution to more common (and smaller dimensional) recursive methods, in terms of both the economic effects of climate change and potential increases in trade barriers, showing the power and efficiency of our computational approach and parallel processing routine.     

Knowing is half the battle: Seasonal forecasts,adaptive cropping systems,and the mediating role of private markets in Zambia

This paper examines how smallholders living in regions where a drought is forecasted adapt their farm practices in response to receiving seasonal forecast information. The article draws on a unique longitudinal dataset in Zambia, which collected information from farm households before and after a significant drought caused by the 2015/2016 El-Niño Southern Oscillation. It finds that farmers residing in areas forecasted to be drought-affected and receiving seasonal forecast information are significantly more likely to integrate drought tolerant crops into their cropping systems compared to similar households not receiving this information. Moreover, the probability that a farmer implements these adaptive farm management strategies in response to seasonal forecast information is found to increase substantially as the number of private grain buyers in the farmers’ village increases. This suggests that climate change adaptation and resilience strategies that integrate the generation and dissemination of weather information with agricultural market development can achieve greater impact on farmers’ adaptive responses than approaches that treat these activities in isolation.     

Climate Change,Innovation, and Economic Growth: The Contributions of William Nordhaus and Paul Romer

ABSTRACT

William Nordhaus and Paul Romer shared the 2018 Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel for their work on long-run macroeconomic analysis. Nordhaus adapted the neoclassical growth model to study climate change, while Romer developed a model of innovation-based growth. The authors provide two distinct explanations of what drives growth, and employ contrasting methodologies for interpreting the results of their mathematical models. Macroeconomic policy in general, and climate policy in particular, would benefit from better integrating the theory and methods of these two laureates.     

政策不确定性对公司投融资行为的影响研究

本文以2003-2013年中国A股上市公司的财务数据和31个省市自治区地方官员的变动数据为样本,采用地方官员变动率作为地方政策不确定性的代理变量,研究了政策不确定性对企业投融资的影响。研究发现,政策不确定性显著降低企业的债权融资,但是对股权融资影响不显著。政策不确定性对企业投资的影响存在两种渠道,一是通过降低企业融资来影响投资,二是通过企业资本运作降低融资对投资的影响系数,即政策不确定性越高,企业债权和股权融资对投资的正向作用会越小,这种作用机制在国有企业、大企业等与政策联系紧密的企业中作用更为显著。融资可获得性是政策不确定性影响投资的重要前提之一,融资可获得性较小时,政策不确定性显著降低了企业投资;在融资可获得性较大时,政策不确定性影响不显著。加强长期制度建设,降低政策不确定性,对于稳增长具有重要意义。