Chinese farmers are often accused of overusing pesticides that play a crucial role in enhancing crop yield by reducing losses to crop pests. Pesticide overuse has caused a series of negative health and environmental e...Chinese farmers are often accused of overusing pesticides that play a crucial role in enhancing crop yield by reducing losses to crop pests. Pesticide overuse has caused a series of negative health and environmental externalities. This paper quantiifes the productivity effect and the optimal amount of pesticides in rice, cotton and maize production in China from the economic perspective. Using survey data col ected in 2012 and 2013, both Cobb-Douglas and Weibul damage control speciifcations are used to estimate the production function. Results show that pesticides have statistical y signiifcant pro-ductivity effect on crop yield. On the condition of Weibul damage control speciifcations, the marginal products of 1 kg of the active ingredients of pesticides for rice, cotton and maize are 71.06, 22.73 and 98.45 kg, respectively. However, 57, 64 and 17%of the actual amount of pesticides are overused for rice, cotton and maize, respectively. Moreover, the productivity effect of pesticides would be overestimated using Cobb-Douglas speciifcation without incorporating a damage control agent.展开更多
This study analyzes the effect of ship size on the liner service configuration by establishing an economic model. The service configuration is characterized by the distance of service and the number of calling ports. ...This study analyzes the effect of ship size on the liner service configuration by establishing an economic model. The service configuration is characterized by the distance of service and the number of calling ports. A study ease is presented for illustration. At last such a conclusion is drawn that given a fixed profit, the ship size will change with the extension of service in the same direction, while the change rate of ship size is a little higher than that of the extension of service.展开更多
There is no convincing evidence to prove that China＇s Lewis turning point （LTP） arrived in 2004-2005, as suggested in some of the existing literature. Employing data from the National Bureau of Statistics of China ...There is no convincing evidence to prove that China＇s Lewis turning point （LTP） arrived in 2004-2005, as suggested in some of the existing literature. Employing data from the National Bureau of Statistics of China for 70,000 rural households and following the method proposed by Minami （1968） to identify the Lewis turning point in Japan, the present study reassessed the reaching of the LTP in China and found that China＇s economy reached the LTP around 2010. From a regional perspective, China ＂s eastern region reached the LTP in 2010 and its central and western regions are now approaching the turning point. After arriving at the LTP, China＇s rural economy will face three key tasks.＂ safeguarding grain security, promoting economic restructuring and realizing agricultural modernization. To cope with the shortage of human capital in agriculture production and the challenge of the tight balance between grain supply and demand, the Chinese Government should improve the human capital training system, accelerate agricultural modernization and guarantee national grain security.展开更多
基金financial support from the National Natural Science Foundation of China (71173014 and 71210004)the China Scholarship Council (201306030053)
文摘Chinese farmers are often accused of overusing pesticides that play a crucial role in enhancing crop yield by reducing losses to crop pests. Pesticide overuse has caused a series of negative health and environmental externalities. This paper quantiifes the productivity effect and the optimal amount of pesticides in rice, cotton and maize production in China from the economic perspective. Using survey data col ected in 2012 and 2013, both Cobb-Douglas and Weibul damage control speciifcations are used to estimate the production function. Results show that pesticides have statistical y signiifcant pro-ductivity effect on crop yield. On the condition of Weibul damage control speciifcations, the marginal products of 1 kg of the active ingredients of pesticides for rice, cotton and maize are 71.06, 22.73 and 98.45 kg, respectively. However, 57, 64 and 17%of the actual amount of pesticides are overused for rice, cotton and maize, respectively. Moreover, the productivity effect of pesticides would be overestimated using Cobb-Douglas speciifcation without incorporating a damage control agent.
基金The National Natural Science Foundation of China (40635026)
文摘This study analyzes the effect of ship size on the liner service configuration by establishing an economic model. The service configuration is characterized by the distance of service and the number of calling ports. A study ease is presented for illustration. At last such a conclusion is drawn that given a fixed profit, the ship size will change with the extension of service in the same direction, while the change rate of ship size is a little higher than that of the extension of service.
文摘There is no convincing evidence to prove that China＇s Lewis turning point （LTP） arrived in 2004-2005, as suggested in some of the existing literature. Employing data from the National Bureau of Statistics of China for 70,000 rural households and following the method proposed by Minami （1968） to identify the Lewis turning point in Japan, the present study reassessed the reaching of the LTP in China and found that China＇s economy reached the LTP around 2010. From a regional perspective, China ＂s eastern region reached the LTP in 2010 and its central and western regions are now approaching the turning point. After arriving at the LTP, China＇s rural economy will face three key tasks.＂ safeguarding grain security, promoting economic restructuring and realizing agricultural modernization. To cope with the shortage of human capital in agriculture production and the challenge of the tight balance between grain supply and demand, the Chinese Government should improve the human capital training system, accelerate agricultural modernization and guarantee national grain security.
