Energy and CO2 emission relationships in the NAFTA trading bloc: a multi-regional multi-factor energy input–output approach

The North-America Free Trade Agreement (NAFTA) has brought together the economies of Canada, Mexico, and the US into forming one of the largest trading blocs worldwide (within the top CO₂ emitters). However, the current global protectionist discourse threatens the agreement. This paper analyzes the energy and energy-related CO₂ emission relationships between NAFTA countries in 2014 to gain insights into the climate change implications of current integration and the possible cancelation of the agreement. The analysis is performed with a multi-regional version of the multi-factor energy input–output model. The results show that NAFTA has not built a single integrated energy system, though it has helped reduce energy-related CO₂ emissions. Moreover, if NAFTA is not revoked, further integration would depend on the capacity of the Mexican energy sector to converge to the performance of its trade partners’ energy sectors. Conversely, a broken deal would induce negative environmental externalities.     

Modified efficient importance sampling for partially non‐Gaussian state space models

The construction of an importance density for partially non‐Gaussian state space models is crucial when simulation methods are used for likelihood evaluation, signal extraction, and forecasting. The method of efficient importance sampling is successful in this respect, but we show that it can be implemented in a computationally more efficient manner using standard Kalman filter and smoothing methods. Efficient importance sampling is generally applicable for a wide range of models, but it is typically a custom‐built procedure. For the class of partially non‐Gaussian state space models, we present a general method for efficient importance sampling. Our novel method makes the efficient importance sampling methodology more accessible because it does not require the computation of a (possibly) complicated density kernel that needs to be tracked for each time period. The new method is illustrated for a stochastic volatility model with a Student's t distribution.     

Logics,Leaders, Lab Coats: A Multi‐Level Study on How Institutional Logics are Linked to Entrepreneurial Intentions in Academia

Situated in the context of academia, this study integrates ideas from institutional theory, person‐environment fit theory and leadership research to conceptualize and examine the cross‐level link between the organizational‐level institutional logic of research commercialization and the entrepreneurial intentions of researchers. Multi‐level analyses based on a sample of 254 researchers working for 85 research group leaders in 49 German research institutes reveal that two distinct attributes of research group leaders – that is, their track records of entrepreneurial behaviour and their entrepreneurial intentions – play a significant role in transmitting the organizational‐level logic to the individual level. We also observe a complementary interaction between organizational‐level commercialization logic and the entrepreneurial track records of leaders. We discuss how these findings advance our understanding of science commercialization through academic entrepreneurship and how they inform institutional theory and theory development in other domains of entrepreneurship research.     

陕西省耕地利用转型与粮食产量耦合关系研究

[目的]研究陕西省耕地利用隐形变化与产量的耦合关系,以此优化粮食生产系统的指导方式,提高陕西省粮食产量,协调陕西省耕地利用转型与粮食产量的耦合关系。[方法]文章运用变异系数法,以粮食生产的"投入指标"为评价依据,耕地利用强度由地均化肥施用量、有效灌溉比、复种指数及地均农业机械动力表征等4个指标构成,以及利用2005~2015年陕西省粮食产量,分析其耕地利用转型和粮食产量耦合关系时空演变。[结果]2005~2015年间陕西省各地市耕地利用强度数值上逐年增大,但空间布局变化较分散;从粮食产量方面来看,陕西省各地市粮食产量整体有所增长,空间分异特征较为明显;耕地利用转型与粮食产量高耦合值区增加,低耦合区值逐渐减少;从空间上看,陕西省中部地区耕地利用转型与粮食产量耦合度越来越高。[结论]陕西省耕地利用转型与粮食产量耦合度在2005~2015年间呈现耦合度逐渐增加的态势,耕地利用转型对粮食安全具有有利影响。     

基于三阶段SBM-Malmquist指数的粮食生产用水绿色效率研究——以宁夏为例

目的 农业可持续发展离不开粮食生产用水效率,探明宁夏区域内粮食生产用水特征有助于提高该地区农水利用效率,实现农业绿色发展。方法 文章以粮食水足迹作为投入指标,粮食灰水足迹作为非期望产出指标,采用三阶段超效率SBM-Malmquist模型,对2006—2020年宁夏18个县区粮食生产用水绿色效率进行了测算。结果 （1）受粮食产量、播种面积以及种植结构的影响,宁夏粮食生产水足迹、灰水足迹地域分异明显,由北向南依次减少;（2）不同粮食品种灰水足迹不同,玉米的灰水足迹最多,造成的污染最严重,主要原因在于玉米播种面积较广,单位面积施氮量大于小麦和水稻;（3）剔除环境因素后发现,环境变量会夸大综合技术效率,导致不同地区粮食生产用水绿色效率不同。结论 研究发现：宁夏粮食生产用水绿色效率高于平均值的地区,如银川、永宁县、贺兰县等,主要受技术效率的影响;而低于平均值的地区,如平罗县、同心县、泾源县,受技术效率影响的同时也受到技术进步的影响。为此,宁夏农业生产用水管理要因地制宜,分区施策,在加大技术创新投入的同时,重点关注单位面积氮肥施用量;继续推进节水型农业,实现粮食生产用水绿色效率的稳步提升。     

农村劳动力转移对小麦生产环境效率的影响路径研究基于并行中介效应模型的实证

[目的]近年来中国粮食生产带来的环境问题已经不容忽视,而计算环境效率可以直接反映粮食生产对生态环境的影响,认清粮食生产的环境代价,并促进中国粮食生产向更可持续的方向发展。[方法]文章以中国三大主粮之一小麦为例,基于1990—2018年15个小麦主产省区面板数据,采用SBMDEA方法测算了中国主产省小麦生产的环境效率,并进一步建立并行中介效应模型考察了劳动力转移对小麦生产环境效率的影响机制。[结果]中国小麦生产环境效率的平均值为0.649,可以看出目前中国小麦生产环境效率水平仍然较低,并且自2000年开始均呈现出递减的趋势,这说明小麦生产背后的生态成本也越来越高。[结论]农村劳动力转移虽然能够促进小麦规模化生产改善环境效率,但是总体影响仍为负向,而财政支农水平、有效灌溉率、机械化水平和小麦最低收购政策对生产环境效率具有显著的正向影响。     

人力资本对贫困地区农村家庭产出的贡献基于黑龙江省的实证分析

[目的]"打赢脱贫攻坚战,是今明两年必须完成的硬任务",剩余贫困人口的脱贫和已脱贫人口的发展亟需释放贫困地区人力资本的力量。人力资本在脱贫阶段演进过程中起到不同的作用,是提高贫困地区农村家庭产出和实现脱贫的核心与关键。[方法]文章通过实地调研验证人力资本对脱贫的作用机理,并为实证分析提供数据支持,依据人力资本与贫困地区农村家庭产出的均衡方程,建立回归模型,结合人力资本在生产函数中的意义及规模报酬不变的条件约束,判断人力资本贡献率对农村家庭产出优化的影响。[结果]实地调研表明脱贫意愿对人力资本构成影响较大;回归分析表明人力资本对贫困家庭产出贡献大于资金资本,也大于知识技术资本;优化规划表明人力资本的积累有助于实现贫困地区农村家庭产出规模优化。[结论]应从健康状况、脱贫能力和脱贫意愿等方面加强人力资本积累,通过共享平台支撑促进人力资本与其他资本有机融合,以人力资本为核心构建内生脱贫模式。     

Output Gap Estimation and Monetary Policy in China

Using the Bayesian multivariate Beveridge-Nelson decomposition method, this paper estimates China's output gap based on a multivariate dynamic model featuring distinct interactions among real output, inflation, money, and the exchange rate in China during the period 1980-2010. The authors compare the statistical nature and potential forecasting effects of the resulting multivariate gap measure on monetary policy with those of the output gap measures based on univariate models. The empirical results show that only the measure based on the multivariate system significantly predicts monetary policy, which indicates that the output gap estimated by the multivariate system contains more information than the traditional measures for macroeconomic policy adjustments do.     

Empirical Evidence on Corporate Risk‐Shifting

We study empirically whether nonfinancial firms’ behavior is consistent with systematic risk‐shifting. We compare firms’ operating risk before and after a debt issue, under the assumption that if there is any risk‐shifting it is most likely to occur right after a debt issue. We document a significant increase in firms’ operating risk, even after adjusting for industry influences. The risk‐shifting is higher for firms with no subsequent debt issues, and for firms with lower credit ratings. Other determinants are earnings volatility, size of debt issue, and whether the bond is callable.     

集成运放的一些使用技巧

目前集成技术飞速发展且集成芯片已被广泛应用 ,为了充分利用集成在一个芯片上的两个运算放大器性能互相匹配的特点 ,本文从三个方面介绍了合理使用集成运算放大器的几种技巧。其中 ,利用集成在一个硅片上的两个运算放大器的输入失调电压极其温度漂移相互补偿的原理 ,组成了失调电压极低的运算放大器 ;根据输入电阻的自举扩展原理 ,利用集成在一个硅片上的两个运算放大器组成的反向比例运算放大器具有很高的输入电阻和较高的电压放大倍数 ;根据差动放大电路的输出电压方式 ,利用集成在一个硅片上的两个运算放大器组成的差动输出运算放大器 ,最大线性输出电压范围比一个集成运算放大器的最大线形输出电压范围大一倍。且适用于不接地负载。