Bandwidth selection for local linear regression smoothers

Summary. The paper presents a general strategy for selecting the bandwidth of nonparametric regression estimators and specializes it to local linear regression smoothers. The procedure requires the sample to be divided into a training sample and a testing sample. Using the training sample we first compute a family of regression smoothers indexed by their bandwidths. Next we select the bandwidth by minimizing the empirical quadratic prediction error on the testing sample. The resulting bandwidth satisfies a finite sample oracle inequality which holds for all bounded regression functions. This permits asymptotically optimal estimation for nearly any regression function. The practical performance of the method is illustrated by a simulation study which shows good finite sample behaviour of our method compared with other bandwidth selection procedures.     

Inequality and welfare evaluation of heterogeneous income distributions

This paper establishes the principles that should govern the welfare and inequality analysis of heterogeneous income distributions. Two basic criteria – the equity preference condition and the compensation principle – are shown to be fundamentally incompatible. The paper favours the latter, thereby vindicating the traditional method of dealing with heterogeneous samples. However, inequality and welfare comparisons will usually be well defined only if equivalent incomes are obtained using constant scale factors; and researchers will need to distinguish clearly between inequality of nominal incomes and inequality of living standards. Furthermore, household observations must always be weighted according to family size.     

Pension prospects of minority ethnic groups: inequalities by gender and ethnicity

Minority ethnic groups have low income in later life from private pensions, partly due to shorter employment records in Britain since migration. Yet disadvantage and discrimination in the labour market, as well as differences in cultural norms concerning women's employment, may lead to persistence of ethnic variation in private pension acquisition. Little is known about the pension arrangements made by men and women in minority ethnic groups during the working life. This paper examines the extent of ethnic disadvantage in private pension scheme arrangements and analyses variation according to gender and specific ethnic group, using three years of the British Family Resources Survey, which provides information on over 97,000 adults aged 20-59, including over 5,700 from ethnic minorities. Both men and women in minority ethnic groups were less likely to have private pension coverage than their white counterparts but the extent of the difference was most marked for Pakistanis and Bangladeshis. Ethnicity interacted with gender, so that Blacks showed the least gender inequality in private pension arrangements, reflecting the relatively similar full-time employment rates of Black men and women. A minority ethnic disadvantage in private pension coverage, for both men and women, remained after taking account of age, marital and parental status, years of education, employment variables, class and income. The research suggests that minority ethnic groups - especially women - will be disproportionately dependent on means-tested benefits in later life, due to the combined effects of low private pension coverage and the policy of shifting pension provision towards the private sector.     

Forecasting Accuracy of Alternative Techniques: A Comparison of U.S. Macroeconomic Forecasts

This article introduces and discusses a new measure of the relative economic affluence (REA) between income distributions with different means. The REA measure D is applied to the U.S. white and black household income distributions of 1967 and 1979. The measure D shows that the REA of the white households with respect to the black households decreased from 1967 to 1979. This conclusion contrasts with those obtained by applications of distance or quasi-distance functions. It is shown in this study that REA measures and distance functions address different and relevant issues. An REA measure deals with the relation “more affluent than” and defines a partial strict ordering over the set of pairs of income distributions—that is, the relation is asymmetric and transitive—whereas a distance function accounts for the dissimilarity between distributions without imposing an ordering relation and hence fulfills the symmetry property.     

局部凸拓扑空间上的广义拟变分不等式

本文讨论了局部凸拓扑空间上的一类广义拟变分不等式问题。在适当的单调和连续性条件下,利用KKM定理和多值映射的不动点定理作为工具,得到了一个广义拟变分不等式解的存在性定理。所得结论是文献[1]的结果的改进。     

基于线性矩阵不等式的牵制控制策略分析

研究复杂动力学网络的同步牵制控制问题.通过引入牵制控制,对具有大规模节点网络中的小部分节点实施线性反馈控制策略,使得整个网络的所有节点均达到同步.针对一类一致连结的耦合复杂网络模型,采用线性矩阵不等式的方法给出了实施牵制控制达到同步的充分条件.该条件表明,选择牵制异质网络中度较大的节点可能更容易使得网络实现同步.特别地,对于特定的内部耦合矩阵和足够大的耦合强度,只要对网络中任一节点实施牵制控制就可以保证整个网络同步的实现.数值仿真验证了上述结论的有效性.     

中国收入分配不平等对经济增长影响的研究

文章利用中国30个省、直辖市、自治区1981-2005年的面板数据，运用面板数据模型分析中国收入分配不平等对经济增长的影响，结果表明中国短期内城乡收入差距有利于经济增长。     

Gender in Academic Career Tracks: The Case of Korean Biochemists

How important is academic performance in obtaining a tenure‐track position in academic science? I use data on Korean biochemists and analyze them from both institutionalist and gender perspectives. In so doing, I illustrate the ways academic performance and gender interact with one another to maintain a gender barrier for Ph.D.s entering an academic career. The main findings are as follows. First, academic productivity did influence the job market outcomes, but the male scientists benefited from publications in both SCI and non‐SCI journals, whereas the female scientists benefited only from those in SCI journals. I also found a positive effect of overseas doctoral training only for the female scientists. Such analysis suggests that women as a minority in academic science are pressured to prove their legitimacy through more rigorous criteria of academic performance. Thus, ostensibly gender‐neutral rules of academic performance can be applied in such a way as to maintain gender inequality.     

加权Ky Fan不等式

用Jessen不等式证明了加权的KyFan不等式成立，证法简短，还证明了与之相应的另一个加权不等式．     

Overcoming the Glass Barriers: Reflection and Action in the ‘Women to the Top’ Programme

Numerous equality programmes have been launched with the aim of promoting a more gender equal work life, yet little substantial action has been reported. This article presents a study of the Women to the Top programme in Sweden, supported by the European Union (EU) and aimed at promoting more women into top management positions. The research suggests that large‐scale projects assembling such heterogeneous actors as industry representatives, politicians and scholars tend to generate further reflection and discussion rather than promoting adequate and highly needed action. Drawing upon Brunsson's distinction between action rationality and decision rationality, the relatively modest effects of large‐scale equality programmes are examined, not in terms of a lack of commitment or competence on the part of the participants but as a matter of the disjunction between reflection and action. Reconciling reflection and action, that is, emphasizing not only reflection on gender inequality but also privileging various forms of practical action (such as new policies, the appointment of female managers, restructuring gendered wage inequalities or new recruitment procedures), is therefore a top priority for policymakers desiring more substantial changes in the gendered outline of industry.