Domestic help and the gender division of domestic labor during the COVID-19 pandemic: Gender inequality among Japanese parents

The enduring COVID-19 pandemic has gradually transformed our everyday lives. This study focuses on changes in work and family arrangements, with particular focus on changes in domestic help, and examines its impact on the division of domestic labor. Using a social survey of work and the family conducted in November 2020 and May 2021, the results show that from January 2020 (pre-pandemic) to May 2021, approximately 40% of respondents experienced a reduced gender gap for housework and childcare, while a large gender gap is still observed in the absolute frequency of undertaking domestic labor. Some lifestyle changes triggered by the pandemic, such as an increase in the use of takeaways or delivery meals, and the expansion of working from home, are found to be able to contribute a shift toward more equal sharing of domestic labor. However, the fact that the access to such lifestyle changes is more common among those with a relatively high income or high educational background suggests that the lifestyle changes imposed by the pandemic may exacerbate class disparities in the gender gap in domestic labor. Furthermore, the results show that decreased kinship support results in a greater childcare burden being placed on women.     

Estimation of odds ratios under order restrictions

A new method for estimating a set of odds ratios under an order restriction based on estimating equations is proposed. The method is applied to those of the conditional maximum likelihood estimators and the Mantel-Haenszel estimators. The estimators derived from the conditional likelihood estimating equations are shown to maximize the conditional likelihoods. It is also seen that the restricted estimators converge almost surely to the respective odds ratios when the respective sample sizes become large regularly. The restricted estimators are compared with the unrestricted maximum likelihood estimators by a Monte Carlo simulation. The simulation studies show that the restricted estimates improve the mean squared errors remarkably, while the Mantel-Haenszel type estimates are competitive with the conditional maximum likelihood estimates, being slightly worse.     

Fluctuations of grasshopper populations on aMiscanthus sinensis grassland

Summary Population densities of the three grasshopper species onMiscanthus sinensis grassland in the Kawatabi IBP Area, Japan,Parapleurus alliaceus, Mongolotettix japonicus andChorthippus latipennis, were estimated principally by the release-and-recapture method for five years from 1968 to 1972. The total number of individuals of all three grasshopper species was about 42 per 100m² in August. The number of individuals ofP. alliaceus adult, the dominant species on this grassland, showed a tendency to decline during the five years, though the amplitude was not so large. The number of eggs laid was, however, nearly constant and the mortality from the second nymphal instar to adult was relatively low and constant during the survey period. The weather conditions during the periods of egg and the first instar, such as snowfall and temperature decreasing, are suggested to be one of the factors causing variation in numbers. Contributions from JIBP-CT No. 145. A part of this study was supported by the special project, “Studies on the dynamic status of biosphere”, sponsored by the Ministry of Education.     

On f-tests and linear hypothesis in a general linear model

A simple method of setting linear hypotheses testable by F-tests in a general linear model when the covariance matrix has a general form and is completely unknown, is provided. With some additional conditions imposed on the covariance matrix, there exist the UMP invariant tests of certain linear hypotheses. We derive them to compare the powers with those of F-tests obtained under no restrictions on the covariance matrix. The results are illustrated in a multiple regression model with some examples.     

Admissibility of Test Procedures for Linear Hypotheses in General Linear Model

This article shows that an F-test procedure is admissible for testing a linear hypothesis concerning one of the split mean vectors in a general linear model and an F-test procedure is also admissible for testing a linear hypothesis concerning another of the split mean vectors in the same model. These results are proved by showing that the critical functions of the tests are unique Bayes procedures with respect to proper prior distributions set in common for the null hypotheses and for the alternative ones, respectively.     

Overwintering ecology of two social halictine bees,Lasioglossum duplex andL. problematicum

Summary Overwintering of two social halictine bees,Lasioglossum duplex (Dalla Torre) andL. problematicum (Blüthgen), was studied. InL. duplex many females stay near the old nests, each female preparing a hibernaculum separated from the natal nest. InL. problematicum most females overwinter communally within the natal nest. This difference in overwintering habits relates to the social structure in the next spring.L. duplex is nearly always solitary in spring although later becoming eusocial, whereas many nests ofL. problematicum are polygynous, beginning in early spring.L. duplex overwinters much deeper ( ) in the soil than doesL. problematicum ( ), but both species are safe from drops in soil temperature, which is above 0°C even in midwinter, and the bees' supercooling points are lower than −6°C. This cold resistance and the storage of sufficient food in the crop are reflected in the winter survival, which is much higher (79%) than the rate of successful nests in the spring active phase (25%). Bionomics of the eusocial halictine beeLasioglossum duplex VII. Contribution No. 2654 from the Inst. Low Temp. Sci.     

大众文化的美学

关于大众文化,我们希望更多地是从美学的视角进行探讨,分析高雅趣味解体之后消费文化与大众传媒之间的审美关系;审视大众文化的奇趣现象以及应时之作应有的审美地位;阐释艺术复制品与拷贝文化的审美价值,进而梳理其中的存在样态,使接受者更多地了解有关大众文化的美学存在与形式。     

在华日资企业经营管理者当地化分析

本文通过对在华日资企业的问卷调查,研究分析了日资企业在华经营管理者当地化的现状以及阻碍其进程的因素。中国籍员工已经成为日资企业经营管理的中坚力量,越来越多的中国人开始在日资企业担任重要职务,推进经营管理者的当地化进程已成为几乎所有日资企业的共识。同时也发现,部分日资企业在华投资时间的长短与经营管理者当地化程度的高低并不完全成正相关关系。