peculiarity of the Japanese divorce system. However, in 2011, a provision that an agreement on visitation and child support may be made is provided in a new civil code （Art.766）.
Consequently responsibility for the welfare of children falls on the mother.
Now where does that leave a single mother and her children? The social situation of single mothers is very severe. Namely single mothers have to work, however there is wage differential and problems of job security caused by gender discrimination.
Next Iʼd like to show you statics about wage disparity.
ⅴ The situation of single mothers after divorce
Divorce of determination Judicial Divorce Divorce by mediation
The Joint Custody of Children after Divorce : A Comparison of Japanese law and Italian law The Graph 6 shows wage disparities between male and female workers13. In 2012, womenʼ s wages were merely 70 percent to those of men. Wage disparities between male and female workers in Japan is second only to Korea of the OECD（the Organization for Economic cooperation and Development）Countries14. Moreover this disparity increases as workers get older. Further more regarding women with children, Japan has the biggest wage disparity of the OECD countries15.
However it is important to note that this womenʼs wages reflects only those of women who can get full-time employment. In other words, it doesnʼt include female temporary workers. Actually it is difficult for women to get full-time work. Thus, many females are forced to take temporary positions. The next graph relates to temporary workers. The Graph 7 shows the rate between genders of temp workers.
As this graph shows, female workers account for 70% of all temporary workers.
Aforementioned even if a woman is fortunate enough to get a full-time position, she will only earn 70% of her male counterpart and many female workers canʼt get full-time work16.
13 For wage disparities in Japan, see Masumi MORI, “Nihon no Seisabetsu Chingin （Wage disparities be-tween Gender in Japan ）”, Yuhikaku, 2005.
14 See the investigation of OECD, Figure 13.1, The Gender pay gap in “Closing the Gender Gap 2012”. Ac-cording to this investigation, on average, wages of female workers are 84％ to those of male workers in OECD countries.
15 See supra. note 14. According to Figure 13.3, The price of motherhood is high across OECD countries, statistics on wage disparities between male and female full-time workers from 25 to 44 years old, hav-ing children under 16 years old, indicate that the average difference in wages is 78％, however, the difference in Japan is 39％. It is the largest wage disparity of all.
16 For disparities in labour between genders in Japan, see “Josei to Roudou（Women and Labour）”, edition of Chisa FUJIWARA and Kazuyo YAMADA, Otsuki-shoten（2011）”, Mutsuko ASAKURA, “Roudou to Gender no Houritsugaku（Jiurisprudence in Labour and Gender）”, Yuhikaku, 2000.
male workers
29.8%
female workers
70.2%
The Ministry of Internal Affairs and Communications 2012
Graph 7 The rate of temporary workers according to gender
single mothers must work as she canʼt get husbandʼs support. Now consequently how is the life of the mothers and children going?
The Graph 8 shows the annual income of single mothers and 2 parent family with children. And of these single mothers, divorced mothers account for 80%. In Japan, unmarried mothers are very few, less than 8% of all single mothers. Therefore, single mothers of this survey are made up mostly of divorced mothers.
The left bar shows the annual income of a working single mother. It is about 17,920 USD
（US dollars）. And the second bar shows the household income included extra income, for example family allowance.
However even if extra income is included, the total annual income of a single mother is merely 28,811 USD. Now how much is the average annual income of a 2 parents family with children? The right bar shows totals 65,148USD.
Comparing these amount, the annual income of a single mother is far less than half17. As mentioned, single mothers are poor, which of course means that under the sole custody system without fatherʼs support, also their children are poor18. Considering the high educational costs in Japan, the fact that the children canʼt afford to get higher education means 17 For poverty of single mothers, see Osamu AOKI, “Gendai Nihon no mienai Hinkon（Invisible Poverty
in modern Japan）”, Akashi-shoten, 2003,
18 For poverty of children, see, Osamu AOKI, Gendai no Hinkon to Fubyodo（The modern poverty and Disparities）, Akashi-shoten, 2007. Naomi YUASA, Gendaikazoku to Kodomo no Hinkon（Poverty of Chil-dren and Modern Family, in Kodomo no Hinkon（Poverty of Children）, Akashi- shoten,
0 20000 40000 60000 80000
Single mother's
income
Single mother and extra income
2 Parent family with
Children
USD rate in JPY on June 1, 2013 17,920 USD
28,811 USD
65,148 USD
The Ministry of Health, Labor and Welfare 2011
Graph 8 Annual Income of Single Mothers and 2-Parent families
with Children
The Joint Custody of Children after Divorce : A Comparison of Japanese law and Italian law loss of opportunity in the future.
Moreover, the problem is not limited to economic issues. Problems extend to physical and psychological care, for example, educational and child-rearing issues. Especially in adolescent ages, there are many complicated and delicate problems. For example, in Japan there are serious problems with bullying at school19 and juvenile stay-at-home20, that is students who refuse to go to school. However, mothers canʼt ask the father for help because of lack of personal contact with their ex-husband. Mothers must resolve these difficult problems on their own.
In short, sole custody brings disadvantages to children because children canʼt get appropriate or sufficient help from the other parent.
7. Conclusion
Aforementioned, Japanese law maintains a sole custody system after divorce. And in almost cases parental authority is granted to mothers. However many fathers donʼt pay child support, and arenʼt involved in their childrenʼs lives. As a result, only mothers assume responsibility for children. Owing to gender discrimination, mothers are forced into poverty.
Motherʼs poverty brings their children into poverty under the sole custody system.
When gender discrimination exists in a system in which sole custody is granted mothers, children are likely to suffer many disadvantages. Therefore having mothers assume sole custody may not be beneficial to children. Therefore both parents must assume responsibility for their children jointly. For these reasons, I propose a joint custody system in Japan21. Parents must take Joint responsibility for their children. I believe that Japan needs to introduce a system of Joint Custody like the Italian system. Also, as mentioned earlier, a sanction system is needed to prevent poverty of children after divorce and to guarantee personal contact with both parents for the sound development of children.
本論文は、拓殖大学政治経済研究所・平成24年度研究助成の研究成果の一部である。
（原稿受付 2013年6月12日）
19 For Bullying at school in Japan, see Yoji MORITA, “Ijime no Kokusaihikaku Kenkyu（The International Comparative Study on Bullying at school）”, Kaneko-shobo, 2001.
20 For Stay-at-home students in Japan, see Sohei IDE, “Hikikomori no Shakaigaku（The Sociology on Stay-at-home students）” Sekaishisousha, 2007. Yoji MORITA, Futoukou gensho no Shakaigatu（The Sociology on phenomenon of Stay-at-home students）” 2nd edit. Gakubunsha, 2005.
21 There has not been court decision which referred to Joint Custody in Japan. Following theories assert Joint Custody: Yoshiko INUBUSHI, “Kazoku <Shakai to Hou>” n.26,2010,p. 35, Noriko MIZUNO, “Ka-zokuhou kaisei ―Konin.Oyakohou Wo Chuushinni（The reform of Family law）” Jurist,n.1384,2009, p. 4.
Michihiro TANAKA, “Shinkenhou no Rippoukadai（The legislative problem of the law of parental right）” , Houritsu Jihou, NihonHyouronsha, vol.83, n.12,2011, p. 27.
はじめに
本稿を含む一連の論稿の目的は，これまでに拙稿において構築した国際秩序の分析枠組をもと に，現在の国際政治学における国際秩序論を再検討することである。その分析枠組とは，社会シ ステム論の視点から国際社会を把握しようとするものであり，国際社会システムにおける機能的 要件の維持と変更，およびシステム構造の安定と変動に重点を置いた分析枠組である。
現在の国際政治学における国際秩序論は，現実主義，自由主義，新マルクス主義などの学派に よって視点が大きく異なっており，その結果，それぞれの議論は異なった独自の秩序要因に重点 を置いた一面的な見方になっている。さらに，学派の内部において，同じ秩序要因にもとづいた 議論でさえ，国際秩序が安定か不安定かの結論が異なっている。それゆえ，本論稿では，国際社 会における秩序を一つの視点から捉えるのではなく，社会学的な分析アプローチであり，かつ複 合的な分析を得意とする社会システム論的な視点を取り入れることによって，国際秩序をより多 面的にかつ総合的に考察することを目的とする。
これまで，機能主義的社会システム論の国際社会への適用を試み，国際社会システムにおける 機能的要件がどのように充足されているかを，またそれらが国際社会システムの構造の安定性を