基于组合赋权和AHP法的农机化可持续发展研究

[目的]通过定量分析,明确不同准则层对农业机械化可持续发展的影响,衡量农机化可持续发展在时间维度上的演变趋势。[方法]建立了新疆农机化可持续发展评价指标体系,并构建了2001~2015年可持续发展水平评价指标关系数据模型。提出了组合赋权和专家法相结合的判断矩阵构建方法,并基于层次分析法(Analytic Hierarchy Process,AHP)分别定量分析了2001年和2015年农机化可持续发展状态。[结果](1)2015年新疆农机化可持续发展水平达到了80.31,和2001年相比提高了1.284 7倍。(2)从准则层来看,新疆可持续发展水平在农机化作业能力、农机化经济效益和农机化发展能力方面分别提高了69.70、85.94和48.64,但资源消耗方面的得分下降了1.12。[结论]2001~2005年新疆农业机械化可持续发展水平在作业能力、经济效益和发展能力等因素推动下进一步提升;揭示资源环境影响是约束农机化可持续发展的主要因素。从新疆农业机械化发展现状来看,文章方法得出的量化结果与实际情况较接近,表明研究方法有效和可行。     

Does inflation cause gold market price changes? evidence on the G7 countries from the tests of nonparametric quantile causality in mean and variance

This article utilizes the newly proposed nonparametric causality-in-quantiles test to examine the predictability of mean and variance of changes in gold prices based on inflation for G7 countries. The causality-in-quantiles approach permits us to test for not only causality in mean but also causality in variance. We start our investigation by utilizing tests for nonlinearity. These tests identify nonlinearity, showing that the linear Granger causality tests are subject to misspecification error. Unlike tests of misspecified linear models, our nonparametric causality-in-quantiles tests find causality in mean and variance from inflation to gold market price changes between the 0.20 quantile and the 0.70 quantile, implying that very low- and high-price changes in gold markets are not related to inflation. These changes should be related to other sources, such as financial shocks and exchange market shocks. We find support that gold serves as a hedge against inflation, but only in the mid-quantile ranges, i.e. quantiles from 0.20 to 0.70. Our results show that gold does not serve as a hedge against inflation during periods when gold market price changes are very low or very high, which are respectively quiet and highly volatile periods.