2015年8月、文部科学省編集の高校保健副教材『健康な生活を送るために』に、「妊娠のしやすさ」の加齢による減少を誇張したグラフが掲載された。本稿では、この事件の経過と、このグラフの元となった研究について、解説と評価をおこなう。また、科学的研究への信頼と男女平等 (男女共同参画基本計画) に関して、この事件からえられる教訓を述べる。

This paper reports the results of a literature review on "An Estimate of the Natural Fecundability Ratio Curve" by Bendel and Hua (1978, Social Biology 25). The estimation of this work was the origin of a falsified chart on women's age-fertility profile that was featured in a high school health education material published in 2015 by the government of Japan. The author searched citation databases and collected 23 works citing the study. A review of the 23 works showed that biases and unreliability of the Bendel-Hua estimation had been pointed repeatedly. The results imply that the chart would be inappropriate for educational use, even if it were not falsified. Both the Japanese government and academics are responsible for the inappropriate chart being used without a comprehensive literature review to insure the reliability of scientific knowledge.

The current Japanese gender-equal policy aims for an equal share of paid and unpaid work between women and men through reducing both childcare and paid working hours. This paper criticizes the practicability of the policy. First, a logical analysis of an official document (1996) demonstrates the tacit assumption that all men are full-time workers. Under this assumption, the normal working hours applied to all men, as well as the normal standard of housework in the society, limit the domain of possible time allocation between women and men. Second, numerical simulations of gender equalization under the current policy are done with the data for the average amount of time spent on paid and unpaid work by women and men aged 30-39 surveyed in 2000 by the NHK Broadcasting and Culture Research Institute. The results show that gender-equal time allocation never realizes under the current policy. Finally, the author suggests four modifications to the policy: (1) reduction of housework as well as childcare, (2) shorter working hours than the current goal, (3) keeping the total amount of time spent on work and housework, and (4) promotion of men's family-centered career.

A secondary analysis of comparable time-use data (arranged by the NHK Broadcasting Culture Research Institute; the survey dates vary from 1985 to 1990) from Japan, Canada, US, UK, Netherlands, Denmark, and Finland, is conducted by means of a new mathematical procedure to decompose time-use-by-sex arrays distinguishing between effects of marginal distribution and effects of equalization in lifestyle.<br /> <br /> Let a and y denote unpaid housework time by women and by men respectively; x and b denote paid work time by women and by men. Let the marginals be denoted as follows: F = a + x ; M = b + y ; T = F + M ; U = a + y. The index of sex-typed time-use, which is a variant of Yano Masakazu&#039;s hubyoudou sisuu [inequality scale], is defined as d = T - 2 ( x + y ). Because of the empirical constraint that women&#039;s and men&#039;s amount of labor (F and M) should balance with each other, d cannot exceed C = T-2|F-U|; this C depends on the marginals and presents a structural constraint on individuals&#039; option. The appropriate estimator of the prevalence of the gender-equal lifestyle is E = (C-d)/C, a coefficient standardized to be margin-free.<br /> <br /> Finally a two-dimensional (E x C) scatterplot of the seven countries is interpreted with the aid of a welfare state typology by Alan Siaroff (1994): (1) the gender equality in time-use (E) corresponds to the gender equality in the paid labor market; (2) in the Netherlands and in Japan the ceiling of sex-typed time-use (C) depends on the length of the standard paid working time, whereas among the other five countries, to which Siaroff referred as Protestant welfare states, C diverges according to the family welfare orientation.

The distribution of housework time spent by &quot;katei huzin&quot; [housewives] is drawn from the National Time Use Survey (conducted by the NHK Broadcasting Culture Research Institute). The difference between their housework time and the standard working time is used to estimate how much labour can be supplied by housekeepers. The findings show that the estimated amount of time housekeepers could supply is too small to offset the labour shortage that is predicted arise from demographic changes.

A secondary analysis of comparable time-use data (arranged by the NHK Broadcasting Culture Research Institute; the survey dates vary from 1985 to 1990) from Japan, Canada, US, UK, the Netherlands, Denmark, and Finland, is conducted by means of a new mathematical procedure to decompose time-use-by-sex arrays distinguishing between effects of marginal distribution and of equalization in lifestyle. Let a and y denote unpaid housework time by women and by men respectively; x and b denote paid work time by women and by men. Let the marginals be denoted as follows: F=a+x; M=b+y; T=F+M; U=a+y. An index of the sex difference in time-use, which is a variant of Yano Masakazu's hubyoudou sisuu [index of inequality], is defined as d=T -2(x+y). Because of the empirical constraint that women's and men's work time (F and M) should balance with each other, d cannot exceed the ceiling of asymmetry C=T-2 ｜ F－I｜; this C depends on the marginals and presents the structural limit of individuals' option. The appropriate estimator of the prevalence of the gender-equal lifestyle is E=(C-d)/C, a coefficient standardized to be margin-free. Finally a two-dimensional (E X C) scatterplot of the seven societies is interpreted with the aid of a welfare regime typology by Alan Siaroff (1994). (1) The gender equality in time-use (E) corresponds to the gender equality in the paid labor market. (2) In the Netherlands and in Japan the ceiling of asymmetry (C) depends on the length of the standard paid working time, whereas among the other five societies, to which Siaroff referred as Protestant welfare states, C diverges according to the family welfare orientation.

This paper discusses the effect of education on Japanese women's continuous full-time employment (CFE). Excluding women employed in family enterprises, we focus on the modern sexual division of labor-the division between occupational and domestic labor. First, we confirm with 1955-95 Japan census data that the number of full-time working women has been maintained, despite a substantial rise in their educational standards. Then we analyze personal histories of Japanese women collected through two nationwide surveys at 1985 and 1995.<BR>It seems, upon the first examination, that university graduates tend to pursue CFE. But this correlation between education and CFE disappears when the teaching field is exempted. The correlation is only a conditional one, made up with the known fact that the teaching profession provides significantly greater opportunities for CFE to highly educated women. Since the number of teachers is independent of the number of university graduates, it is difficult to relate fluctuations in the CFE rate and the educational standards.<BR>A logistic regression (excluding teachers) reports that women's education would have no significant effect on CFE, even if their husbands' occupational status and their own occupational status before marriage were kept constant.<BR>The results reject theories of the schooling effect, such as the Sexist Education theory and the Human Capital theory. We conclude that school has no effect on CFE, and that changes in educational standards can hardly alter the sexual division of labor.

Qualitative Comparative Analysis with Boolean algebra which was developed by Charles C. Ragin is not only a comparative method for intemational comparison, but also a method which has many other applications. Though this method has some merits, of course, it has some demerits also. One of the demerits is that this method cannot take independent variables other than 2-value variables. The aim of this paper is to remedy this limitation, namely to advance a new Boolean Analysis with multi-value variables as independent variables.

Discussed is how occupational structure determines women&#039;s quitting behavior on marriage and childbirth, which is the main factor of discontinuity of women&#039;s work-force participation in Japan. With the exception of those who employed in family enterprises, we restrict our attention to the modern sexual division of labor, which is the division between occupational work and domestic labor. Personal histories are drawn from a 1985 nationwide survey. The samples are divided into two cohorts: born before 1945 and after. Three hypotheses compete in explaining changes between the two cohorts.<br /> The first hypothesis argues that higher occupational status reduces quitting rate (QR) because of its economic advantage and better occupational condition. The data show contrary to the hypothesis: Higher occupations exhibit higher QR.<br /> <br /> The second hypothesis argues that, in workplace under the Japanese management, sex segregation between stable and mobile employment increases QR through encouraging gender ideology. We reject this hypothesis because changes in inter-firm mobility of men and women are inconsistent with changes in QR.<br /> <br /> The third hypothesis argues that opportunities of advancement (OA) discourage women from quitting. To measure OA, we feature two factors: (1) size of internal labor markets and (2) frequency of inter-firm upward mobility. We observe just this hypothesis expect: Decrease in both of the factors is necessary and sufficient to increase QR.<br /> <br /> The results show OA to be the main and direct cause of promoting continuity of women&#039;s work-force participation. It is also suggested that Japanese women have made no gain in OA in the postwar period, which stiff situation may be the reason why QR has been keeping the level of 60%.

This paper measures longitudinal changes in women's participation in employment. Excluding women employed in family enterprises, we focus on the modern sexual division of labor, the division between occupational and domestic labor.<BR>In the 1948-94 figures of women's employment status based on the Japan Labor Force Survey, we observe an increasing number of part-time workers and a stable number of full-time workers.<BR>Further details are given with personal histories of Japanese women collected through a 1985 nationwide survey. [1] Of those who worked full-time before marriage, only 20% remain working full-time at the childrearing stage (CRS). [2] Of those who were not employed at CRS, 20% enter full-time employment at post-CRS. [3] The numerical values of 20% are consistent among all cohorts. [4] More women enter part-time employment at post-CRS.<BR>The findings imply a partial shift in the postwar sexual division of labor : Japanese women have poured into short-term or part-time employment, while there has been no change in their participation in long-term and full-time employment. This means a separate movement in the barrier against employment of women. To explain that movement, we should reject the accepted theory that the barrier is monolithic.