This paper provides a review on China＇s meat trade for the 2000–2012 period and discusses its future development, with reference to China＇s grain trade. With marginal decreases in meat exports and slight increases ...This paper provides a review on China＇s meat trade for the 2000–2012 period and discusses its future development, with reference to China＇s grain trade. With marginal decreases in meat exports and slight increases in their imports, China＇s net imports of major meat products（including pork, beef, mutton and poultry but excluding meat offal） were just below 1 million tons in 2012, dwarfed by China＇s net imports of grains which reached 66.7 million tons in the same year. This slow growth in meat trade seems to contradict earlier expectations on increasing meat demand and imports, based upon projected shifts in consumption patterns driven by rapid per capita income growth. Several plausible explanations of this paradoxical trade pattern are offered, including mass imports of feed grains, persistent（but shrinking） gaps between Chinese and international meat prices, tariff barriers, and non-tariff measures. In the near future China may not be able to maintain such a lower profile on the world meat markets, as per capita income is projected to continue to rise and domestic production cost advantages erode due to rising labor costs. A model-based projection exercise indicates that under plausible assumptions China＇s meat imports may rise sharply by 2030.展开更多
A supersaturated design （SSD）, whose run size is not enough for estimating all the main effects, is commonly used in screening experiments. It offers a potential useful tool to investigate a large number of factors ...A supersaturated design （SSD）, whose run size is not enough for estimating all the main effects, is commonly used in screening experiments. It offers a potential useful tool to investigate a large number of factors with only a few experimental runs. The associated analysis methods have been proposed by many authors to identify active effects in situations where only one response is considered. However, there are often situations where two or more responses are observed simultaneously in one screening experiment, and the analysis of SSDs with multiple responses is thus needed. In this paper, we propose a two-stage variable selection strategy, called the multivariate partial least squares-stepwise regression （MPLS-SR） method, which uses the multivariate partial least squares regression in conjunction with the stepwise regression procedure to select true active effects in SSDs with multiple responses. Simulation studies show that the MPLS-SR method performs pretty good and is easy to understand and implement.展开更多
基金financial support from the National Natural Science Foundation of China(71203096 and 71303112)the Doctoral Program of Higher Education,China(20120097120042 and 20123204120017)
文摘This paper provides a review on China＇s meat trade for the 2000–2012 period and discusses its future development, with reference to China＇s grain trade. With marginal decreases in meat exports and slight increases in their imports, China＇s net imports of major meat products（including pork, beef, mutton and poultry but excluding meat offal） were just below 1 million tons in 2012, dwarfed by China＇s net imports of grains which reached 66.7 million tons in the same year. This slow growth in meat trade seems to contradict earlier expectations on increasing meat demand and imports, based upon projected shifts in consumption patterns driven by rapid per capita income growth. Several plausible explanations of this paradoxical trade pattern are offered, including mass imports of feed grains, persistent（but shrinking） gaps between Chinese and international meat prices, tariff barriers, and non-tariff measures. In the near future China may not be able to maintain such a lower profile on the world meat markets, as per capita income is projected to continue to rise and domestic production cost advantages erode due to rising labor costs. A model-based projection exercise indicates that under plausible assumptions China＇s meat imports may rise sharply by 2030.
基金supported by the National Natural Science Foundation of China （Grant Nos. 10971107, 11271205）, the ＂131＂ Talents Program of Tianjin, and the Fundamental Research Funds for the Central Universities （Grant Nos. 65030011, 65011481）.
文摘A supersaturated design （SSD）, whose run size is not enough for estimating all the main effects, is commonly used in screening experiments. It offers a potential useful tool to investigate a large number of factors with only a few experimental runs. The associated analysis methods have been proposed by many authors to identify active effects in situations where only one response is considered. However, there are often situations where two or more responses are observed simultaneously in one screening experiment, and the analysis of SSDs with multiple responses is thus needed. In this paper, we propose a two-stage variable selection strategy, called the multivariate partial least squares-stepwise regression （MPLS-SR） method, which uses the multivariate partial least squares regression in conjunction with the stepwise regression procedure to select true active effects in SSDs with multiple responses. Simulation studies show that the MPLS-SR method performs pretty good and is easy to understand and implement.
