Anomalies in the Foundations of Ridge Regression: Some Clarifications

Several anomalies in the foundations of ridge regression from the perspective of constrained least-square (LS) problems were pointed out in Jensen & Ramirez. Some of these so-called anomalies, attributed to the non-monotonic behaviour of the norm of unconstrained ridge estimators and the consequent lack of sufficiency of Lagrange's principle, are shown to be incorrect. It is noted in this paper that, for a fixed Y , norms of unconstrained ridge estimators corresponding to the given basis are indeed strictly monotone. Furthermore, the conditions for sufficiency of Lagrange's principle are valid for a suitable range of the constraint parameter. The discrepancy arose in the context of one data set due to confusion between estimates of the parameter vector, β , corresponding to different parametrization (choice of bases) and/or constraint norms. In order to avoid such confusion, it is suggested that the parameter β corresponding to each basis be labelled appropriately.     

因子分析方法在城镇家庭人均消费支出分类中的应用

消费水平是衡量一个地区经济发展水平的重要指标,对区域制定宏观经济政策、区域间经济的协调发展、国家经济的长远发展,具有重要的现实意义。我国地大物博,地区间经济发展水平不同,民俗不同,同时由于人们对消费的喜好程度不同,所以支出也不尽相同。因子分析可以把复杂的数据用较少的综合指标来表达,从而达到降维和分类的目的。本文通过对我国2012年的31个省份地区城镇居民家庭人均消费支出及消费结构的数据进行研究分析,得到相对客观的评价结果。该评价结果与国家统计局的公布的排序基本一致。     

Forecasting national activity using lots of international predictors: An application to New Zealand

We assess the marginal predictive content of a large international dataset for forecasting GDP in New Zealand, an archetypal small open economy. We apply “data-rich” factor and shrinkage methods to efficiently handle hundreds of predictor series from many countries. The methods covered are principal components, targeted predictors, weighted principal components, partial least squares, elastic net and ridge regression. We find that exploiting a large international dataset can improve forecasts relative to data-rich approaches based on a large national dataset only, and also relative to more traditional approaches based on small datasets. This is in spite of New Zealand’s business and consumer confidence and expectations data capturing a substantial proportion of the predictive information in the international data. The largest forecasting accuracy gains from including international predictors are at longer forecast horizons. The forecasting performance achievable with the data-rich methods differs widely, with shrinkage methods and partial least squares performing best in handling the international data.     

女大学生就业问题实证研究——基于西安六所大学高校的数据分析

大学生就业难越来越成为当今社会的热点问题,女大学生做为一个特殊的就业群体,在一定程度上受到性别的歧视。本文在人力资本等相关理论的基础上,利用层次分析法对六所大学的调研数据进行实证分析。在实证研究基础上文章针对该现状做出了多方面视角的分析,提出了构建男女平等的就业环境、提高女大学生自身综合素质等建议。     

基于SPSS的区域物流竞争力评价分析——以浙江省为例

运用SPSS软件,对浙江省各地区区域物流竞争力进行实证研究,通过主成分分析和聚类分析法的结合,对11个市区域物流竞争力进行综合评价并分类,得出结论并提出建议。     

Measurement of Dynamic Efficiency in Production: An Application of Data Envelopment Analysis to Japanese Electric Utilities

The purpose of this paper is to measure productive efficiencies when a firm employs quasi-fixed inputs that cannot be instantaneously adjusted to their optimal levels. To this end, data envelopment analysis (DEA) is extended to a dynamic framework so that investment behavior can be modelled with the efficient production frontier. Based on the work of Nemoto and Goto (1999), we show how the efficiencies of quasi-fixed inputs and their adjustment processes are evaluated. An application to Japanese electric utilities over the 1981–1995 period delivers empirically plausible results and proves the usefulness of the procedure.