社会信任、感知价值对农户秸秆还田技术采纳意愿的影响——基于鄂豫两省样本农户的实证

目的 研究揭示社会信任、感知价值对农户秸秆还田技术采纳意愿的影响机制和效应。方法 文章基于社会嵌入理论和感知价值理论,以秸秆还田为例,利用湖北、河南1 776份农户调查数据,采用结构方程模型（SEM）实证分析社会信任、感知价值对农户秸秆还田技术采纳意愿的影响,并探讨不同分化水平下农户采纳意愿的差异性。结果 （1）社会信任、感知利益对农户采纳意愿具有显著正向影响,而感知风险具有显著负向影响;（2）社会信任主要通过感知利益间接作用于农户秸秆还田技术采纳意愿,感知风险的中介作用不显著,其中介效应分为别为0.165和0.001;（3）从多群组分析结果来看,低水平分化和高垂直分化农户的社会信任对其秸秆还田技术采纳意愿的影响更强烈。结论 政府应构建农户高度信任的外部环境,提高农户多维度价值感知,针对不同分化水平的农户制定差异化宣传策略,以切实增强农户采纳秸秆还田技术的积极意愿,实现秸秆综合利用与生态保护的双重目标。     

Estimating persistent and transient technical efficiency and their determinants in the presence of heterogeneity and endogeneity

We develop an estimation procedure that generates consistent estimates of the technology parameters, long-run (persistent) and short-run (transient) technical inefficiencies and the marginal effects of their determinants for the stochastic frontier model developed by Colombi et al. (2014, Journal of Productivity Analysis 42, 123) and Kumbhakar et al. (2014, Journal of Productivity Analysis 41, 321). Our approach accounts for three sources of potential endogeneity: (i) unobserved heterogeneity; (ii) simultaneity of input use with both types of technical efficiency; (iii) potential correlation of the noise term with the regressors. Using this approach we examine the effect of direct payments and farm size on the persistent and transient technical efficiency of French crop farms before and after the European Union's Common Agricultural Policy decoupling reform of 2003. Our results show that subsidy payments per hectare of utilised agricultural land had a significant positive effect on persistent technical efficiency and a significant negative effect on transient technical efficiency during the period before decoupling. For the period after the reform, the effect of subsidies is found to be significantly negative for persistent technical efficiency and insignificant for transient technical efficiency. The overall effect of subsidies on technical efficiency is found to be negative in both periods, albeit substantially lower in the period after decoupling. The effect of farm size on technical efficiency is found to be significant only for the period prior to the reform: it reduced persistent technical inefficiency but increased transient technical inefficiency during that period.     

Trends in Agricultural Incomes: An Analysis at the Select Crop and State Levels in India

India's agricultural sector is at a crossroads, facing challenges of stagnation in crop yields, non‐remunerative prices, falling crop incomes and tardy responses from public service systems. There are reports of peasant suicides due to non‐profitability of farming. However, scant empirical evidence is available on changes in real income and wages in the Indian agricultural sector. The present study uses data from the National Accounts Statistics and Cost of Cultivation Surveys to analyse the changes in real income and discusses the underlying reasons. The study reveals that the purchasing power of farmers has remained low and has worsened over recent years. The value of crop output has increased, but a disproportionate rise in input costs has resulted in a fall in crop incomes in several states, with the agriculturally developed Punjab being an exception. Interestingly, real wage rates for agricultural labour have shown an increasing trend, indicating improvement in the welfare of labour.     

Crop Insurance as a Strategy for Adapting to Climate Change

Financial insurance for extreme events can play an important role in hedging against the implications of climate change. This paper combines a comprehensive estimation strategy and a unique panel dataset to study the role of financial insurance in farmers' welfare under uncertainty. Data are drawn from a large Italian farm panel dataset. We find that (i) demand for insurance products is likely to increase in response to climatic conditions, and (ii) that the use of insurance reduces the extent of risk exposure. We also find that farms growing more crops are less likely to adopt the insurance scheme. This confirms what is found in the theoretical literature. Crop diversification can be a substitute for financial insurance in hedging against the impact of risk exposure on welfare.     

热轧带钢滚筒式切头飞剪关键技术进步

总结了30年来热轧带钢滚筒式切头飞剪关键技术进步,包括机械结构创新设计和最优化剪切系统等。     

分析企业在江苏省典型秸秆收购模式中的角色

本文以提高江苏省秸秆规模化收集和储运效率为背景,从当前江苏省典型收购模式出发,结合整个收储运过程中存在的问题,发现企业在整个过程中所扮演角色的局限性。指出随着生物质能的应用逐渐成为一种必然趋势,企业作为最直接的参与者所应该承担的责任。企业应该顺应形势,在受政府扶持的同时,发挥主观能动性,合理转换角色,推动秸秆规模化收集和储运效率的提高。     

Time‐varying Hedge Ratios: A Principal‐agent Approach

We use the classic agency model to derive a time‐varying optimal hedge ratio for low‐frequency time‐series data: the type of data used by crop farmers when deciding about production and about their hedging strategy. Rooted in the classic agency framework, the proposed hedge ratio reflects the context of both the crop farmer's decision and the crop farmer's contractual relationships in the marketing channel. An empirical illustration of the Dutch ware potato sector and its futures market in Amsterdam over the period 1971–2003 reveals that the time‐varying optimal hedge ratio decreased from 0.34 in 1971 to 0.24 in 2003. The hedging effectiveness, according to this ratio, is 39%. These estimates conform better with farmers’ interest in using futures contracts for hedging purposes than the much higher estimates obtained when price risk minimisation is the only objective considered.     

Is There a Viable Market for Area-Based Crop Insurance?

The performance of area yield insurance and farm-level multiple peril crop insurance is analyzed for cotton and soybean production in Georgia and South Carolina. The analysis improves on many previous studies by utilizing actual farm-level yield data and by comparing the two types of insurance products not only for actuarially fair premium rates but also for actual unsubsidized and subsidized premium rates. Results suggest that, even in heterogeneous production regions, area yield insurance may be a viable alternative to farm-level insurance when premium rates for farm-level insurance contain large positive wedges.