日本「少子化的三十年」：考察與啟示

A study on Japan's 'thirty years of declining birthrate'

日本自1990年的「1.57衝擊」（前一年的總和生育率僅1.57，為當時史上最低）迫使全體社會正視少子化問題以來，走過了三十個年頭。本文從「定義與指標」、「成因與影響」、「對策與成效」等三個方面來總結日本過去三十年的少子化問題與對策。首先據定義，少子化指的是「總和生育率長期低於遞補水準生育率，且幼齡人口少於高齡人口」的狀態；除此兩要件外，每年出生數的推移也有參考價值；前述指標可產生輿論效果並或影響著日本的政策形成。其次梳理日本「出生動向基本調查」的歷次調查結果，發現日本少子化的可能成因隨著時間呈現動態變化；而在少子化的影響方面，限制範圍後可大致分為對「勞動」與對「育兒」的影響，且與性別及城鄉差異有關。最後檢視日本「第三次少子化社會對策大綱」等政策計畫所設定的具體實施項目、目標與實績，可知實施項目正逐漸增加且變得龐雜，在實績方面則達成程度不一。日本「少子化的三十年」呈現一個充滿動態變化的過程，不但影響著少子化現象的指標多元，且國民的生育觀念與行為也隨著時間有所不同，促使了政府在對策上必須不斷修正與擴充。

It has been 30 years since the ''1.57 shock' in 1990 (the total fertility rate of previous year was 1.57, the lowest in history at the time) pushed the whole Japanese society to face the problem of declining birthrate. This paper summarises Japan's low fertility problems and countermeasures over the past three decades from three aspects: ''definition and indicators', ''causes and effects', and ''measures and effectiveness'. Firstly, ''low fertility' is defined as a state in which ''the total fertility rate is below the replacement level fertility and the youth population is smaller than the elderly population'. Secondly, a review of the findings of the National Fertility Survey reveals that the possible causes of birthrate declining in Japan have been changing dynamically over time. In terms of the impact of low fertility, it can be broadly divided into the impact on ''labour' and the impact on ''childcare', and is related to gender and urban-rural differences. Finally, a review of the implementation items, goals and performances set out in the policy plans, such as the Third Outline of Measures to Cope with Society with Declining Birthrate, shows that the implementation items are increasing in number and scope, and the actual performance varies from one to another. The ''thirty years of declining birthrate' in Japan presents a process full of dynamics, with a variety of indicators defining the phenomenon of declining birthrate, as well as different childbearing attitudes and behaviours over time, prompting the government to constantly revise and expand its response.