Climate extremes, characterized by droughts and floods, have become one of the major constraints to sustainable improvement of rice productivity. Variety choice, considered as one of the main adaptation measures, could help farmers reduce yield loss resulting from these extremes. Based on a three-year panel survey of 1,080 Chinese rice farms in major rice producing provinces, we study the effect of adopting stress tolerant variety rice as a main adaptation measure against climate extremes. Taking into account the endogeneity of adoption behavior, we employ an endogenous switching regression to separately estimate the treatment effects of adoption for adopters and non-adopters. We find that farmers who adopted the new variety increased yield by 537 kg/ha (about 7%), compared with the counterfactual case of no-adoption. In contrast, the farmers who did not adopt, would increase rice yield by 272 kg/ha (about 4 %) if they adopted, much smaller than the adopters. However, adoption of new variety demands more knowledge, better education, more intensive management, and higher seed costs. As a policy implication, expansion of public extension services could help relax these restrictions.
Constructing a theoretical framework and using a survey data of 294 customers from 25 supermarkets in Beijing, this paper studies the willingness to pay (WTP) for additive-free Mooncakes in Beijing and finds that age and income are important for WTP for “food safety” in China. Income is positively correlated with the WTP and there is an inverted-U-shaped relationship between age and WTP. This study indicates that consumers in Beijing are willing to pay 5.80 Yuan more for an additive-free Mooncake, which provides a good policy benchmark for the government regulation on food additives. Furthermore, the theoretical framework also provides a good benchmark for understanding WTP in the future study of food safety.
In order to solve the problem of design domain degeneracy because of the man-induced independent separation of mechanical and control system in the electro-mechanical integration,the concurrent design model of structural and control integral system was put forward based upon the virtual work equation.That is,launching out into the dynamics virtual work equation,deducing the dynamics model of the variable concurrent integration,combining with the theories of optimum structure and optimum control,to establish the model of integral optimum design.Taking ultrasonic amplitude bar of wire bonding machine as an instance,aiming at the improvement of location stability and response,the validity was verified in accordance with the analytic solution in the design feasible zone which is under clear continuation and alteration.The design model and outcome cast light on the concurrent design of micro electro-mechanical system which is under the constraint of the extremity action.
This paper employs the production function-based method proposed by Just and Pope (1978, 1979) to explicitly analyze production risk in the context of Chinese grain farming and climate change, and test for potential endogeneity of climate factors in Chinese grain production. Our results indicate that grain production in south China might, at least in the short run, could be a net beneficiary of global warming. In particular, we find that a 1 °C increase in annual average temperature in South China could entail an increase of grain output by 3.79 million tons or an economic benefit of around USD 798 million due to the increasing mean output. However the impact of global warming in north China is negative, small and insignificant. In addition, Hausman tests reveal no endogeneity of climate variables in Chinese grain production.
Subsidies for temporary laying-up (TLU) are often introduced to support commercial fishers in crises. We studied the effect of a German TLU in response to quota cuts and the COVID-19 pandemic on fishers' revenue frontiers and efficiency by stochastic frontier analysis, and on species composition by fixed-effects models using monthly landings declarations from 2008 to 2020. Own laying-up days increased inefficiency and decreased revenue frontiers. Subsidies were related to outward shifts in the revenue frontier, and were linked to small increases in landings of unregulated marine species. Laying-up periods by other fishers were not related to changes in the revenue frontier or efficiency, but to changes in species composition of unregulated species, away from freshwater species and flatfish, and towards eel and other marine species. Technical efficiency mostly decreased over time, offsetting temporal outward shifts in the revenue frontier.
Purpose The purpose of this paper is to review the theoretical background, methodological extensions, and empirical applications of the Engel curve, which is applied to the research of the change in farmers’ welfare and food demand in China after the economic reform in 1978, compared with the statistics of income and food consumption. Design/methodology/approach This paper mainly uses the traditional method of Engel curve, which is compared with income growth and food consumption, to study farmers’ welfare improvement in rural China. Findings The Engel coefficients identify three different stages for farmers’ welfare change after 1978. The first stage is the period between 1978 and 1988, in which farmers’ welfare has been continuously enhanced due to the institutional bonus of the 1978 economic reform and increased government purchase price of agricultural products. The second stage is the period between 1989 and 1995, in which farmers’ welfare has been slightly deteriorated mainly due to the end of institutional reform bonus, suppressed food prices, relative high inflation, and instable political situation. The third stage is the period after 1995, in which farmers’ welfare returns to a growing path, as the dual price system was abolished, the transition from a planned economy to a market economy had been completed, and the government carried out protective policies for agriculture and started to heavily subsidize agriculture. The Engel coefficient still remained at a very high level at 0.59 in 1995, but it continuously decreased to 0.33 in 2015. The welfare enhancement for farmers mainly results from deepened market-oriented reform, protective policies for agriculture, and prevalent off-farm employment. The Engel coefficient is also linked to food demand elasticities. Along with the decreasing Engel coefficient in the past 40 years, income elasticities also continuously decrease from 0.55 in 1978 to 0.08 in 2015. Food demand is very inelastic now, and any further increase in income will not substantially increase food demand any more. Research limitations/implications Inequality has not been analyzed. Originality/value This paper reviews the methodological advantages of the Engel curves, and uses it to identify different stages of welfare change and estimate income elasticities of food demand for farmers in China after the 1978 economic reform.
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