The 1920s was another turning point in population history in modern Japan. This decade witnessed the emergence of another discourse, summed up in the expression “population problem,” which claimed the population itself – its size, quality, and mobility – was a liability for economic, social, and political stability. Over the decade, public narratives around the “population problem” spurred the government toward establishing policies dedicated to the problem. To fulfill this goal, the government appointed a broad range of population scientists within policymaking and assigned them to collaborate with bureaucrats and deliberate on policies based on their expert knowledge. While the collaboration during the 1920s failed to lead to a national population policy, it exhibited a novel way of coproduction between population science and the governing of Japan’s population. The “population problems” imperative compelled the government to work together with population experts in order to manage Japan’s population through policies, while in turn, through policymaking, state bureaucracy became a central site for the population experts to generate and apply their expert knowledge.

The Emergence of the “Population Problem”

The term “population problem” (jinkō mondai), now normalized in contemporary Japanese, was foreign to many people at the turn of the twentieth century.Footnote ¹ However, starting in the 1910s, the expression began to circulate with the rise of popular media. The popular magazine Central Review (Chūō Kōron) introduced the term as early as 1913 in an article authored by Fukuhara Ryōjirō (1868–1932), a Ministry of Education bureaucrat.Footnote ² “Population problem” was also the theme of the third major conference of the Japan Sociological Institute (est. 1913) held in 1915.Footnote ³

However, it was only in the 1920s that the term became genuinely widespread. In 1924, the popular women’s magazine Housewives’ Friend (Shufu no Tomo) defined “population problem” as a current affairs topic and claimed an educated “good wife, [and] wise mothers” ought to know about it.Footnote ⁴ The term also appeared in Diamond (Daiyamondo), a business magazine, where the now mature statesman Gotō Shinpei reflected on the subject.Footnote ⁵ Finally, it was a core subject in the booklet aimed at “proletariats” that was published by the Industrial Labor Research Institute, a front organization of the Japanese Communist Party.Footnote ⁶ By the end of the decade, “population problem” had become a common expression in mass-circulated print media.

The presence of the term during this period was catalyzed by the increased availability of statistical knowledge on the Japanese population.Footnote ⁷ The government had been publishing vital statistics annually since 1899 (see Chapter 2). Furthermore, in 1920, it organized the first population census of “Japan Proper” (naichi) (see Chapter 1).Footnote ⁸ Looking at these population statistics in the first half of the 1920s, experts noted a sign of population growth. According to the 1920 census, the population of Japan – excluding the populations of Karafuto, Taiwan, Korea, the Guangdong Territory, and Micronesia – was 55,963,053, with a total of 11,122,120 households, making the average household 4.89 persons.Footnote ⁹ Between 1921 and 1925, the population kept expanding at a rate between 10.8 and 14.7 per 1,000 persons, which amounted to a natural increase of 673,000 to 913,000 annually. In 1926, more than one million people – 1,004,000, precisely – were added to the existing population for the first time since the Meiji government began to compile population statistics in 1872. The year also witnessed the population figure going over 60 million for the first time, reaching 60,741,000.Footnote ¹⁰

Witnessing this demographic trend, journalists and scholars warned that Japan was currently facing a serious problem in regard to population growth.Footnote ¹¹ In his seminal article “Some Reflections on Overpopulation,” published in Chuō Kōron in July 1927, Yanaihara Tadao, a professor at Tokyo Imperial University and an authority on colonial policy, wrote:

Many social commentators and policy intellectuals shared Yanaihara’s sentiments, defining population growth as a current “population problem.”

The idea of population expansion creating issues for the collective was not new. In the early Meiji period, noted intellectuals expressed their concerns over the sudden visibility of an expanding group of struggling samurais after the government dismantled the social structure that had long privileged them. They characterized samurais as politically volatile, “surplus people” and suggested that the government should come up with appropriate measures to tame them for peaceful nation-building.Footnote ¹³ Likewise, in the mid-1880s, when the fiscal policies under Finance Minister Matsukata Masayoshi caused an economic depression, population expansionists characterized impoverished farmers as “surplus people.”Footnote ¹⁴ In the Meiji period, public intellectuals and officials problematized politically and economically burdensome groups by mobilizing the language of population expansion.Footnote ¹⁵

In the 1920s, an additional perspective found a voice in the debate over population growth. This time, the focus was placed on the effect of overpopulation on the economy, specifically on people’s living conditions. Reminiscing about Japan’s population problems in the 1920s, in 1937 the population policy researcher Ishii Ryōichi identified events that brought misery into people’s economic lives.Footnote ¹⁶ One was the economic recession after WWI. It was exacerbated by the Washington Naval Treaty in 1922, which caused unemployment in the shipbuilding sector due to the limitations imposed on the construction of capital ships in Japan. The following year, the Great Kanto Earthquake hit the capital Tokyo and its vicinity and cost the government billions of yen. Population growth in this context was seen to place pressure on the nation’s economy, causing further unemployment, lowering the living standard, and eventually leading to “difficulty in living” (seikatsunan) – a buzzword within the socialist and labor activism that was burgeoning during this period in response to the economic depression.Footnote ¹⁷ In addition, Ishii thought the United States Immigration Act of 1924, which limited Japanese migration, indirectly worsened people’s living conditions in Japan. When the act was issued, Japan lost an important outlet for its excess population. Consequently, the little island country became even more crowded, which eventually led to the erosion of already limited natural resources. As Ishii saw it, population growth in the 1920s was a problem related to “economic life,” which was made worse by Japan’s disadvantaged position in world politics.Footnote ¹⁸

This way of problematizing population growth triggered an academic debate on the nature of “population problems” among social scientists, especially those with backgrounds in economics. It was sparked by the provocative article, “Give Birth, Multiply,” presented on June 4, 1926 by sociologist Takata Yasuma (1883–1972).Footnote ¹⁹ Going against the mainstream opinion that problematized population growth, Takata claimed that the real population problem was the population contraction due to fertility decline. In stark contrast to the 1910s, the birth rates declined over the 1920s, from 36.2 births per 1,000 population in 1920 to 34.4 in 1928. Takata pointed out how this trend was caused by the growing popularity of artificial birth control among the urban intellectual class. He argued that the population stagnation resulting from the fertility decline among this class was “the most dangerous” for the Japanese as “a weak and disadvantaged racial group” in world politics.Footnote ²⁰ Based on this logic, in the article, Takata urged married couples to make more babies.

As Takata’s statement indicates, his concern was fueled less by the argument linking population growth with poverty and more by the geopolitical perspective, which viewed a large population size as an asset that would help raise Japan’s global position.Footnote ²¹ Takata admitted that the recent economic recession had certainly led to “difficulty in living” among the people in Japan but simultaneously criticized this argument as being based on an introverted perspective that narrowly focused on domestic situations. Takata then urged his colleagues to adopt a broader view and consider Japan’s growing population in relation to its racial and geopolitical struggles within world politics, which were dominated by white, western colonial powers. He explained, “population is indeed a source of every kind of power for a race [minzoku],” therefore, “the larger a population is, the more the race will thrive and its power expand in every possible direction.”Footnote ²² Takata believed Japan could take advantage of its currently growing population to alter its disadvantaged position as the colored colonial power. He claimed, “population increase” was “the only weapon a colored race has to fight against white people.” He even argued that “the colored race must be prepared to face self-destruction [jimetsu]” if it lost the power to grow its population.Footnote ²³ This logic of racial struggle compelled Takata to warn about the danger of declining fertility.

Marxist economist Kawakami Hajime (1879–1946) at the University of Kyoto immediately refuted Takata’s argument.Footnote ²⁴ As Kawakami saw it, population surplus was a problem inherent to capitalism. Kawakami argued that under capitalism, the proportion of invariant capital – the capital allocated to equipment and raw materials – would increase with the mechanization and the increasing scale of production, whereas the proportion of variable capital allotted to wages would decline. Under these circumstances, even if the amount of capital as a whole increased, it would not catch up with the increase in the number of workers, thus eventually generating surplus population and poverty (i.e., “difficulty in living”) among the waged population. For Kawakami, the population problem was by nature a problem connected to the capitalist economy, and overturning capitalism would be the only way to solve it.Footnote ²⁵

Kawakami’s response led to a heated population debate that last for nearly a decade – one involving prominent social scientists such as Nasu Shiroshi, Shinomiya Kyōji, Yoshida Hideo, Sakisaka Itsurō, and Ōuchi Hyōe.Footnote ²⁶ Reminiscing about the decade-long debate, in 1936 the leading economist and population theorist Minami Ryōsaburō concluded that the debate ultimately failed to establish any concentrated efforts, though it did jumpstart a number of research projects.Footnote ²⁷ In turn, postwar social scientists, starting with Ichihara Ryōhei, portrayed the debate as manifesting a deep-seated, inherently unresolvable conflict between the distinctive population theories of Karl Marx and Thomas Malthus.Footnote ²⁸ From a historical point of view, the academic population debate was significant, because it illuminated the growing understanding that population was a dynamic social factor directly impacting the living conditions of the masses and, therefore, “population problems” were invariably synonymous with “social problems” (shakai mondai), another catchword in the public, intellectual, and policy debates during this period.

The public discourse and debate around “population problems” urged government officials to explore policies to tackle wide-ranging social issues associated with population phenomena. The policymaking process showed how the official agenda was shaped by the broader sociopolitical circumstances surrounding Japan at the time.

The Official Response to the Population Problem

Among the many population problems, the government perceived the “food problem” (shokuryō mondai), heightened by population expansion, as the most urgent.Footnote ²⁹ In particular, after the inflation of the cost of rice caused mass protests in 1918, high-rank government officials became concerned that food shortage would not only promote “difficulty in living” but also stimulate political unrest.Footnote ³⁰ To tame the protests, government officials set price controls on rice in the metropole and encouraged the cultivation of Japanese-style rice in colonial Taiwan and Korea. However, this policy led to a sudden rise in the amount of less-expensive rice from Taiwan and Korea in the metropole, and consequently, the government met with harsh criticism.Footnote ³¹ Social commentators explained that the policy of importing colonial rice exposed the government’s failure to raise domestic agricultural productivity enough to feed the “population of Japan Proper” (naichi jinkō).Footnote ³² Under these circumstances, policymakers were presented with the thorny question of how to feed the expanding Japanese population using the country’s limited resource capacity.

Against this backdrop, the government, under the premiership of Tanaka Giichi (1927–29), established the Investigative Commission for Population and Food Problems (Jinkō Shokuryō Mondai Chōsakai, hereafter IC-PFP) on July 7, 1927. Headed by Tanaka and located directly under the cabinet, the IC-PFP was a major government initiative responsible for research and policy deliberation over population and food supply issues. Under Tanaka, Home Minister Suzuki Kisaburō (1867–1940) and Minister of Agriculture Yamamoto Teijirō (1870−1937) became the vice-chairmen. Reflecting the joint vice-chairmanship, the government identified two enquires for the IC-PFP to address: one on population and the other on food issues. The IC-PFP Secretariat met six times between July 17 and October 5, 1927 to deliberate on official inquiries and set the agenda, and it set up two sections (i.e., the Population Section and the Food Section) as specialist deliberation committees.

As is apparent from its name and organizational structure, the IC-PFP’s understanding of population problems was through the lens of the Malthusian dilemma (i.e., the imbalance between population growth and the pace of food production). At the same time, the conflicting view, such as Takata’s that saw population growth as a symbol of expanding national power, also influenced the official characterization of population issues. This was succinctly summarized in the speech Tanaka delivered at the IC-PFP First General Assembly:

As expressed in the speech, the official stance was that the population increase was not ipso facto problematic and, in fact, should be celebrated as a factor promoting the “brilliance of our race.” However, it became a problem when put into the specific context of Japan: Poor resource availability, coupled with the compromised state of the nation’s industry, meant that the country had a limited ability to absorb surplus population. Under these circumstances, continuous population growth would weaken the nation’s capacity to feed its people, saturate the labor market, and eventually lower people’s living standards. Tanaka’s speech implied that the IC-PFP’s agenda in relation to the population problem was in fact more expansive than the simple Malthusian predicament and dovetailed with issues related to the national economy and industry, labor, and resources.

Another significant component of Tanaka’s speech was his explanation of issues related to the national economy and Japanese territory through the intensification of population density. This caricature of population problems was not at all original to Tanaka; on the contrary, it was currently in vogue within the international community of population experts. The idea of population density was at the heart of the World Population Conference held in Geneva in the summer of 1927.Footnote ³⁴ At the conference, participants highlighted issues related to sovereignty, geopolitics, and the economy that arose due to growing population density. They understood the situation as most evident in Europe, the Indian subcontinent, and East Asia – the three world regions that Ernst Georg Ravenstein had once characterized as the “global centers of population.”Footnote ³⁵ One of the American participants, Warren S. Thompson (1887–1950), later portrayed these regions, including Japan, as “danger spots in world population.”Footnote ³⁶ Thompson claimed that the population expansion in these “danger spots” would put further pressure on the land, ultimately catalyzing political and economic disasters on a global scale.Footnote ³⁷ Put in this context, Tanaka’s speech indicated the Japanese government’s awareness of the global consensus forming among the population experts at the time: The earth had bounded space, and the growing population, especially in world regions with the densest populations, would imminently trigger a world crisis.

Also recognizing that the international academic discussion pointed a finger at Japan’s rising population density, the Japanese government resorted to migration to relieve the pressure associated with a rising population in “Japan Proper.”Footnote ³⁸ In 1928, the government issued the Overseas Migration Cooperative Societies Law (Kaigai Ijū Kumiai Hō), which authorized prefectures to organize emigration projects. Responding to the law, in the 1930s, prefectures took a leading role in sending their people abroad, first to Latin America and then to Manchuria and the South Seas.Footnote ³⁹

The official response to the perceived population crisis was not new. In the early Meiji period, responding to the narrative of surplus people, the government mobilized the samurais to colonize Hokkaido.Footnote ⁴⁰ In the mid-1880s, amid the economic depression, population expansionists argued that North America could absorb the population of impoverished Japanese farmers.Footnote ⁴¹ While this premise remained fundamentally unchanged, in the late 1920s, the political environments specific to the period – domestic and international – exhorted government officials to consider making overseas migration an official policy.Footnote ⁴² Within Japan, as the politically suspected left-leaning labor and socialist movements grew in popularity, the government, especially the Home Ministry, which was also in charge of social affairs, began to consider overseas migration as an attractive option for maintaining social order. By targeting populations deemed susceptible to these movements, the government hoped overseas migration would curb the movements’ further growth. Alongside this, a number of diplomatic events – notably the Allies’ refusal of Japan’s proposal to include a racial equality clause in the Treaty of Versailles in 1919 and the US Immigration Act in 1924 – swayed the government’s opinion in favor of overseas migration. Perceiving these diplomatic incidents to symbolize the domination of the racist attitudes of white, western colonial powers within world politics, Japanese political leaders believed that Japan, as the only colored colonial power, should cultivate their own versions of colonial migration in order to take a stand in the political struggles of that time.Footnote ⁴³

Reflecting the government’s agenda, state-endorsed emigration in the late 1920s focused on workers and farmers who were impoverished due to the economic depression, as well as on activities that could directly contribute to Japan’s colonial agenda.Footnote ⁴⁴ In Brazil and Manchuria, it insisted on the principle of “coexisting and coprospering” (kyōzon kyōei), a benevolent colonial development based on the coexistence and coprosperity of the Japanese and native populations.Footnote ⁴⁵ For the Japanese state, overseas migration during this period was a device to solve the labor, social, and population problems within the metropole as well as a way to assert – what the political leaders deemed compromised – Japan’s geopolitical standing in world politics via colonialism.Footnote ⁴⁶ In this context, Japan’s high population density conveniently justified colonial migration.

In addition to political reasons, population density gave an economic rationale for the migration policy. The government portrayed overseas migration also as a means with which to foster what Prime Minister Tanaka called an “industrial economy.” This caricature urged policymakers to see overseas migration as the twin policy of domestic migration. According to this view, overseas migration aimed to alter population density on the macro level, whereas domestic migration – encouraging people to move from more concentrated urban centers to less-dense regions within Japan Proper – was a micro-level attempt to raise the overall level of commercial and industrial productivity by “adjusting” the domestic population density to an optimal level. The logic was as follows: If the government adequately coordinated internal and overseas migration, industrialists could more efficiently deploy their business within both Japan Proper and the colonies. At the same time, migrants, as well as people who remained in Japan Proper, would have more job opportunities and, therefore, enough financial power to stimulate the Japanese economy. This additional rationale not only promoted overseas migration even further but also consolidated the official discourse in favor of internal migration.

Prime Minister Tanaka, as head of the IC-PFP, had internalized this logic when he pondered the population issues. To start with, Tanaka believed overseas migration was merely “one solution to the problem” of a growing population; therefore, he did not think it alone could dissipate the population problem in the metropole.Footnote ⁴⁷ Tanaka believed overseas migration should be carried out in parallel with “policies to make Japan an industrial nation [sangyō rikkoku],” by which he primarily meant economic measures, including “internal migration.”Footnote ⁴⁸ If overseas migration could “relieve” Japan’s population pressure, effective economic measures could also “absorb population.”Footnote ⁴⁹

The IC-PFP Secretariat, headed by Secretary of the Cabinet Hatoyama Ichirō (1883–1959) and comprised of twenty-four bureaucrats from relevant government offices, followed Tanaka’s line.Footnote ⁵⁰ Topics related to migration – domestic and overseas – and the increased economic opportunities dominated the draft of the IC-PFP Secretariat’s reference plan for population policies. The draft reference plan, originally submitted by the Home Ministry’s Bureau of Social Affairs to the Secretariat on August 4, included the following list of subjects that the IC-PFP Population Section should investigate to come up with “specific measures for population growth”:

1. 1. Regarding Measures to Increase Demands in Labor

2. 2. Regarding Measures to Control the Supply and Demand in Labor

3. 3. Regarding Measures for Domestic Migration

4. 4. Regarding Measures for Emigrating out of the Country

5. 5. Regarding Measures to Encourage Migration Generally

6. 6. Regarding the Establishment of Colonial Companies

7. 7. On the Official Administrative Organizations for Migration

8. 8. Regarding Birth ControlFootnote ⁵¹

The list clearly reflected the government’s commitment to using migration and economic development to solve the problem of population growth.

After deliberating on the bureau’s draft several times, the IC-PFP Secretariat approved the modified reference plan in early October. The reference plan was passed on to both sections, and they used it to deliberate on government population policies. The discussion within the Population Section illustrated that a community of population experts, held together by policymaking, was formed alongside the government’s effort to tackle “population problems.” However, these policy experts, with their diverse intellectual backgrounds, presented ideas that were not always in line with the official agenda.

Population Control and Migration: The Experts’ Response

For the Population Section, the IC-PFP summoned twenty-two permanent members and eleven temporary members from the pool of politicians, senior officials, bureaucrats, and population experts from fields as diverse as economics, social policy, colonial policy, statistics, medicine, and public health.Footnote ⁵² On October 12, 1927, the Population Section convened its first meeting. Between then and April 1930, when the IC-PFP dissolved, the Population Section had four section meetings, twenty-four special committee meetings, six draft-making committee meetings, and three Small Committee meetings, and it officially submitted six draft reports and two resolutions in response to the government’s inquiry on population matters.

Generally speaking, the Population Section followed the guidelines stipulated in the IC-PFP Secretariat reference plan,Footnote ⁵³ and so the members at the meeting decided to work on emigration and “labor adjustment” (rōdō chōsei). This focus ultimately culminated in three draft reports, “Measures for Internal and External Emigration,” “Measures Regarding the Adjustment of Supply and Demand in Labor” and “Population Measures for Various Locals Apart from Japan Proper.”Footnote ⁵⁴

However, a closer look at the deliberation process presents a more nuanced picture, testifying to how the policy discussion involved complex negotiations. In many instances during the negotiations, the two groups had divided opinions over the interpretation of population – the IC-PFP Secretariat representing the voice of the government officials and the Population Section expressing the opinion of population experts. To start with, while the Population Section deliberated on emigration and labor adjustment, this did not mean they completely agreed with the Secretariat’s suggestions. Some members of the Population Section’s Special Committee and Draft-Making Committee were skeptical that overseas migration and domestic labor adjustment alone could “have a value, as fundamental measures, to solve the population problem.”Footnote ⁵⁵ Based on this view, they saw a need to come up with a more comprehensive policy that would complement these measures.

In addition, some members of the Population Section disagreed over the IC-PFP Secretariat’s characterization of population measures. Specifically, they did not like that the Secretariat’s draft reference plan portrayed overseas migration not only in relation to the problem of overpopulation but additionally as a geopolitical measure “to establish an international justice by realizing the principle of coexistence and coprosperity.”Footnote ⁵⁶ The member vociferously opposing the political overtones in this description was Nagai Tōru (1878−1973), the bureaucrat and social policy expert leading the discussions in the Population Section. At a Population Section meeting, in front of the Bureau of Social Affairs Secretary Kawanishi Jitsuzō (1889–1978), who was explaining the draft reference plan, Nagai dismissively told: “this kind of manifesto is disagreeable because it sounds like either a small nation’s tale of woe or acts as the mask for an aggressor nation.”Footnote ⁵⁷ After discussions, the Population Section decided that its draft proposal on overseas migration would not include the aforementioned statement.Footnote ⁵⁸ Some in the Population Section were clearly ambivalent about the idea that emigration might be used as a political tool to secure Japan’s global status.

Finally, between the IC-PFP Secretariat and the Population Section, there was a slight discord in the understanding of which measures the government should prioritize. While the Secretariat was mainly concerned about the problems of population quantity, the Population Section was additionally interested in the issues of population quality. The deliberation process on “population control” (jinkō yokusei), which included the topics of birth control and eugenics, attests to this point. Whereas the IC-PFP Secretariat sidelined concerns over the subject, the Population Section spent long hours on it. The outcome of this different attitude was a stark contrast. While the IC-PFP Secretariat’s reference plan put the subject of birth control at the bottom of the aforementioned list, the Population Section produced an independent policy proposal dedicated to measures for population control – one of the six draft reports officially presented by the section during its existence.

In the late 1920s, population quality problems, specifically issues touching on eugenics and birth control, were popular, yet controversial, subject matters.Footnote ⁵⁹ Eugenics, a term coined by Francis Galton in 1883, was almost immediately introduced in Japan as yūzenikkusu, and later yūseigaku, “science of superior birth.”Footnote ⁶⁰ From the start, the intellectuals defined eugenics as a method of “racial improvement” (jinshu kairyō), which the Japanese could incorporate to reach a higher level of civilization.Footnote ⁶¹ This idea became more pervasive after the 1890s, when “race” (jinshu or minzoku) began to hold currency in political discussions and within the articulation of nationalistic sentiments.Footnote ⁶² Especially after Japan acquired Taiwan as a colony in 1895 and won the war against one of the most formidable white race countries in the Russo-Japanese War (1904–5), anthropologists, biologists, geneticists, doctors, and social scientists fervently discussed the political implications of Japan as a nonwhite empire, and actively explored the possibility of applying eugenics to raise Japan’s international profile.Footnote ⁶³ Beginning in the 1910s, events in international politics, including the aforementioned scandal at the Versailles Peace Conference in 1919, further fueled the sentiment that eugenics – now used synonymously with another neologism, “racial hygiene” (minzoku eisei) – was an appropriate measure for Japan to adopt to supersede the white imperial powers. Under these circumstances, publications such as the journal Der Mensch: Jinsei (Humankind), launched in 1905 by the renowned physician and medical historian Fujikawa Yū (1865–1940), offered experts in medicine, biology, psychology, anthropology, and other fields dealing with racial and population sciences an outlet for their fervor for eugenics.

With regard to birth control, an early reference in Japan’s modern history appeared in the 1880s in relation to the criminalization of abortion in 1880 (see Chapter 2).Footnote ⁶⁴ In the 1900s, the neo-Malthusian argument, greatly inspired by the British activist Annie Besant, began to generate public discourse on birth control.Footnote ⁶⁵ However, during this period, the concept of birth control remained largely theoretical.Footnote ⁶⁶ This situation began to change in the late 1910s, when news about the American birth control movement arrived in Japan.Footnote ⁶⁷ In particular, when Margaret Sanger, the doyenne of the American birth control movement, visited Japan in 1922, she greatly influenced the public’s perception of birth control and the popular birth control movement.Footnote ⁶⁸ After Sanger’s Japan tour, Ishimoto Shizue – Sanger’s close friend who became a leader in the Japanese birth control movement – founded the Japan Birth Control Study Group (Nihon Sanji Chōsetsu Kenkyūkai) in May 1922, whose participants included well-known figures such as Abe Isoo, Kaji Tokijirō, Yamakawa Kikue, and Suzuki Bunji.Footnote ⁶⁹ In Kyoto, Sanger’s visit urged the noted biologist and sexologist Yamamoto Senji (1889–1929) to join the birth control activism.Footnote ⁷⁰ Shortly after Sanger’s visit, Yamamoto published The Critique of Mrs. Sanger’s Methods of Family Limitation, which, despite being noncommercial and academic, was phenomenally popular.Footnote ⁷¹ In January 1923, with labor activists based in Osaka, Yamamoto established the Osaka Birth Control Study Group (Osaka Sanji Seigen Kenkyūkai) as an organization specifically dedicated to teaching birth control methods to individuals with more than five children.Footnote ⁷² In February 1925, Yamamoto launched the coterie magazine Birth Control Review (Sanji Chōsetsu Hyōron).Footnote ⁷³ The journal grew and offered a forum where writers and readers could exchange cutting-edge ideas about birth control.

As suggested above, the socialist network – which saw birth control as a tool for liberating the working class from the chains of capitalist exploitation and poverty – provided a strong ideological backbone to the popular birth control campaign during this period.Footnote ⁷⁴ However, precisely because of its link with socialism, the birth control movement had a precarious relationship with the government. Officials viewed socialism as a foreign, dissident ideology undermining state authority and thus suppressed birth control activism because it was associated with socialism. After the government issued the Peace and Preservation Law on May 12, 1925, it actively cracked down on birth control activism, claiming it was inculcating indecent ideas in the public. The police were often present at public gatherings and at times ordered participants to stop meetings on the spot. The government also censored activists’ writings, using indecency as a reason.Footnote ⁷⁵ As far as state authorities were concerned, the socialist birth control movement needed to be nipped in the bud; otherwise, it would agitate the public with subversive foreign ideas and disrupt political order.

Some government officials were concerned about birth control for another reason: It could pose a eugenic risk.Footnote ⁷⁶ As Takata Yasuma suggested, in the 1920s, birth control was becoming increasingly popular among those perceived as biologically “superior” – the able-bodied, educated, affluent class in the cities – and their birth control practices seemed to be lowering the group’s fertility rates. To the dismay of government officials, studies in the mid-1920s confirmed this point, showing fertility decline was more conspicuous among the “intellectual class” (chishiki kaikyū) using birth control than among people in other socioeconomic groups.Footnote ⁷⁷ Seeing this trend, Takata broadcast his “give birth, multiply” argument. Similarly, his colleague Teruoka Gitō (1889–1966), known as the pioneer of labor science and a proponent of social hygiene, characterized the intellectual class’s practices as the “unconscientious propagation of birth control” and warned it would “lead to racial suicide.”Footnote ⁷⁸ Policy intellectuals were acutely aware of this “racial suicide” argument presented by population experts.

Against this backdrop, the Bureau of Social Affairs, which was drafting the IC-PFP Secretariat’s reference plan, included “Regarding Birth Control” as a subject for deliberation within the Population Section, as shown in the aforementioned list.Footnote ⁷⁹ However, the Secretariat’s response was tepid. In the fifth Secretariat meeting on September 21, 1927, Chairperson Hatoyama said that this item could be removed because “the issue will naturally come up in the [Population Section] committee meetings anyway.”Footnote ⁸⁰ After the discussion, the Secretariat decided to drop the item from the original draft of the reference plan and replaced it with “Investigations Regarding the Eugenics Movement,”Footnote ⁸¹ and it was included in the final version given to the Population Section.

Why was the Secretariat hesitant about birth control? Why did it recommend eugenics instead? A plausible reason was that the term “eugenics” embraced broader meanings, including birth control, whereas the reverse was not the case. By adopting “eugenics,” the Secretariat might have left more space for the Population Section to decide which topics to discuss. Another reason, which was more political, was that birth control, and population control more broadly, was a controversial topic at the time, certainly more so than eugenics. At some point in the deliberation process, Secretariat members confessed, “once the [policy recommendation for] the problem of population control is codified as a report and published in society, … [it] could invite quite a few misunderstandings.”Footnote ⁸² Apprehensive of the possibility that the general public would misconstrue the government’s motivation for engaging with birth control, the Secretariat dropped birth control from the reference plan. Therefore, this decision could be interpreted as an attempt to deflect any potential public controversies arising from officially recommending politically contentious measures.

In turn, the Population Section poured much energy into the subject. It even set up an independent Small Committee dedicated to population control, namely, the IC-PFP Population Section Small Committee on Population Control. It had three members: Nagai Tōru, Nagai Hisomu (1876–1957, chair of the Department of Physiology at Tokyo Imperial University), and renowned economist Fukuda Tokuzō (1874–1930). Within the Small Committee, the ideas presented by Nagai Tōru and Nagai Hisomu shaped the contours of the discussion within the committee.

Nagai Tōru, after graduating from the Faculty of Law at Tokyo Imperial University in 1903, embarked on his career as a high-rank government official at the Ministry of Agriculture and Commerce and then at the Ministry of Railways until 1920.Footnote ⁸³ Between 1920 and 1926, he became involved in social policy through his role as a managing director at the Harmonization Society (Kyōchōkai), a half-government, half-private organization established in 1919 to coordinate the labor-management relationship.Footnote ⁸⁴ After gaining a doctorate in economics in 1925, Nagai Tōru established himself as one of the most pursued experts for the government’s social and population policies.

Nagai Hisomu was a key figure in eugenics in this period.Footnote ⁸⁵ In the 1910s, he began to present his eugenic theories widely in professional journals, popular magazines, and newspapers.Footnote ⁸⁶ In 1923, he headed the Japanese Society for Sexology (Nihon Sei Gakkai), and in 1930, he headed the new Japanese Society of Racial Hygiene (Nihon Minzoku Eisei Gakkai).Footnote ⁸⁷ Alongside this, Nagai Hisomu promoted eugenics in policymaking. In the 1910s, as an HHSG member, he lobbied for an independent committee for eugenics within the HHSG.Footnote ⁸⁸ At that time, his plan did not materialize. However, in the 1930s, his campaign – this time to promote a eugenic policy like the one in Nazi Germany – became more readily accepted in policymaking, so much so that it culminated in the establishment of eugenic population policies in the early 1940s.

Within the IC-PFP, Nagai Tōru acted as a core member of the Population Section from the outset, assuming a position in all the subcommittees set up within the section. Applying his expertise, he submitted private proposals for most of the issues deliberated within the section. In turn, although Nagai Hisomu was not a founding member of the Population Section, he quickly became one of the most vocal members after being appointed to the section’s special committee on December 13, 1927.Footnote ⁸⁹ For the Population Section’s Small Committee on Population Control, the two presented draft proposals, and Fukuda came up with a revised proposal based on the two documents.Footnote ⁹⁰

Fukuda was confronted with an enormous task, because both Nagai Hisomu and Nagai Tōru had distinctive, yet strong, opinions regarding birth control and eugenics as solutions to the population problem. Trained primarily in the social sciences, Nagai Tōru maintained that the population problem required a sociological approach. He contended that population was determined by the “social scientific law,” which was “calculated based on the contrast between a population and the social force – the force of a society that by itself acts like a living body.”Footnote ⁹¹ Thus, the population problem “was neither the [Malthusian] problem of food nor the [Marxian] problem of employment” but the problem of the “ratio between society’s productive power and the power of a population to expand.”Footnote ⁹² This idea of population exhorted him to focus on the details of population structure (e.g., sex and age ratio) and population dynamics (e.g., fertility and mortality rates) as critical factors determining the quality of a population. It also urged him to define the population problem as first and foremost a societal problem that occurred primarily when the population structure and its dynamics became distorted.Footnote ⁹³

Based on this logic, Nagai Tōru thought the source of the current population problem was the “phenomenon of high birth, high [infant] death,” which he believed represented the underdeveloped state of the “social organization” and “people’s intellect.”Footnote ⁹⁴ To solve the problem, he believed that the state should establish social policies that would help implement institutions fostering the practice of, what he called, “childcare preservation” (ikuji hozen) instead of popularizing birth control. At the same time, he also acknowledged it would take time for Japanese society to mature enough to accommodate a full range of “childcare preservation” institutions. Thus, Nagai Tōru recommended birth control as an interim measure that should only be implemented until society developed fully.Footnote ⁹⁵

In turn, Nagai Hisomu’s idea about population – which he categorically viewed as synonymous with biological race – was premised largely on eugenics, which he insisted on calling “racial hygiene.”Footnote ⁹⁶ He claimed that recent progress in genetics had clarified how parents’ traits were passed down to children equally, irrespective of social groups. Thus, to improve the quality of the Japanese race, the government should strive to “select the good-quality genetic substance and exclude the bad-quality one” and “eliminate the genealogy of families, for instance, with mental illnesses, prone to tuberculosis, and prone to disability.”Footnote ⁹⁷ Yet, Nagai Hisomu was also skeptical about directly applying Mendelian laws of animal and plant heredity to humans. He thought that human sexual behaviors were unpredictable. Furthermore, it would be unrealistic to arrange interbreeding among different human groups within a controlled environment, as Mendelian geneticists had done with their experimental subjects.Footnote ⁹⁸ For this reason, Nagai additionally relied on the biometric approach to heredity, which had its origins in the Galtonian tradition of eugenics.Footnote ⁹⁹ This eclectic understanding of eugenics underpinned Nagai Hisomu’s activism. In practice, he lobbied for a state policy on eugenic birth control, including sterilization, to improve the genetic composition of the Japanese race.

Over the 1920s, Nagai Hisomu expressed his dissatisfaction that his long-term campaign for eugenic birth control was often mixed up with what he saw as frivolous popular birth control activism. What particularly bothered him was that this activism was propagating birth control among the urban intellectual class, who he thought should procreate more because of their “superior traits” (yūshū na seishitsu).Footnote ¹⁰⁰ Thus, like Takata, Nagai Hisomu believed the birth control movement was damaging the quality of the Japanese race. Specifically, it was stimulating differential fertility, or the widening gap in fertility among different social groups, which, in this case, was symbolized by lowering fertility rates within the urban intellectual class and sustained high fertility in the lower socioeconomic groups. Borrowing from the Darwinian concept of natural selection, Nagai Hisomu called this “reverse selection” (gyaku tōta) and characterized it as “those with inferior traits” (retsuaku na soshitsu no mono) dominating those with “superior traits.”Footnote ¹⁰¹ He saw the question of “reverse selection” as a pressing population problem but also observed that the current debate neglected this issue as it concentrated on the Malthusian problem of overpopulation. To rectify the situation, Nagai Hisomu became convinced that the government should intervene in current birth control practices more proactively. He believed the government should establish eugenic birth control as a national policy and work toward implementing a more regulated birth control initiative targeting “those with inferior traits” to solve the problems of population quantity and quality.

With this in mind, Nagai Hisomu submitted a draft proposal to the Small Committee. The proposal was titled “Draft of a Report on Eugenic Problems,” which clearly demonstrated his conviction that a policy on eugenic birth control was necessary to tackle population issues. The preamble defined the “population problem” as “not simply an issue of population quantity but also something that intends to improve population quality from a eugenic point of view.”Footnote ¹⁰² Following this definition, three out of the nine recommendations in the proposal were about reproductive practices and were aimed to prevent the process of “reverse selection.” Specifically: (1) the establishment of “appropriate institutions enabling consultations on marriage, childbirth, and birth control”; (2) the enforcement of “control over distribution, sales, and advertisement for instruments, pharmaceuticals, and other materials assisting contraception”; and (3) the promotion of “research on various institutions from the eugenic viewpoint.”Footnote ¹⁰³

In contrast, Nagai Tōru’s draft proposal, titled “Measures Regarding Population Regulation,” mirrored his view that the population problem was a problem of population itself, caused by the “current situation of high birth, high death, as well as high marriage and high divorce rates,” and thus claimed the state should implement policies aiming to regulate population structures and dynamics.Footnote ¹⁰⁴ Reflecting his focus on “childcare preservation,” the proposal stressed the necessity for implementing “social institutions protecting women giving birth and preserving childcare” and opportunities to teach men and women about population problems.Footnote ¹⁰⁵ While Nagai Hisomu’s proposal put eugenic birth control at the fore, Nagai Tōru’s draft hid the statement, placing it almost casually in the middle of a paragraph and merely suggesting the government should encourage “investigation and research” on birth control.Footnote ¹⁰⁶

Fukuda, in consultation with Nagai Tōru and Nagai Hisomu, made great efforts to merge the two draft proposals into the final draft report. Having looked at both documents, Fukuda came up with a neutral title: “On Various Measures for Population Control.” After many discussions, the three agreed on the following broad definition of population control:

Based on this understanding, the draft report presented a total of nine policy recommendation items, which were, on the whole, more sympathetic to Nagai Tōru’s social policy approach than Nagai Hisomu’s eugenic recommendations. Echoing the sentiment of the HHSG (see Chapter 2), many of these items were about measures for the promotion of maternal and infant health, public health in rural farming villages and cities, and the prevention of tuberculosis. Only two items were specifically on birth control. With regard to eugenics, it adopted the view presented in Nagai Tōru’s proposal, only recommending “research on various institutions relevant from the viewpoint of eugenics.”Footnote ¹⁰⁸ The draft report was approved at the IC-PFP general assembly on December 19, 1929.

By passing “On Various Measures for Population Control,” the IC-PFP implicitly endorsed population control by means of social policy – and to a lesser extent eugenics – as a solution to the population problem. However, the IC-PFP did not make any further efforts to act on this policy recommendation.Footnote ¹⁰⁹ Consequently, no population control policies came about as a result of the exercise. This was a stark contrast to the draft report on migration submitted by the Population Section, which, as mentioned above, directly corresponded to the Overseas Migration Cooperative Societies Law.

Official Research on the “Population Problem”

While failing to make an actual policy, the Population Section’s deliberation efforts made a significant mark in the history of population science in modern Japan: It paved the way for institutionalizing policy-oriented population research.

As mentioned in the previous chapters, the analysis of population figures comprised a significant part of the daily work of official bureaucrats by this period. However, policy-oriented population research was conducted on a project or ad hoc basis. The need to set up an official, permanent institution dedicated to coordinated, policy-oriented population studies was addressed early on by the members of the Population Section’s Special Committee. Among them, committee member Nitobe Inazō – by now established as a prominent colonial-policy scholar and undersecretary-general of the League of Nations – took a first step. Nitobe, also present at the abovementioned World Population Conference, submitted a written opinion piece to the special committee in the spring of 1929 in favor of a permanent research organization for population issues.Footnote ¹¹⁰ Others agreed with Nitobe.Footnote ¹¹¹ Based on Nitobe’s written piece, Nagai Tōru drafted “The Proposal Concerning the Establishment of a Population Research Institute.”Footnote ¹¹²

The draft recommended the government set up a permanent research organization named the Population Research Institute (Jinkō Kenkyūsho), as either a national institute or a public interest corporation, with the objectives of conducting research on population problems and making recommendations in response to government inquiries.Footnote ¹¹³ The Population Research Institute would consist of “experienced academic specialists” and “bureaucrats in the relevant fields” acting as councilors, as well as a small number of researchers. They would conduct studies on: (1) the population composition, distribution, and dynamics; (2) eugenics and other topics relevant to population control; (3) specific measures on overpopulation; and (4) other population policies and theories.Footnote ¹¹⁴ The members of the institute would be obliged to present and publish their research findings, organize lectures and seminars, and join the “international councils on population” and dispatch representatives to its general meetings.Footnote ¹¹⁵

Based on Nagai Tōru’s proposal, the Population Section made the resolution, “Matters Concerning Setting Up a Permanent Research Organization Specialized in Population Problems,” which the IC-PFP passed and submitted to the government on March 29, 1930. The resolution claimed that, given the complex nature of population problems, the government would “take a wrong course” and “make errors in setting the standards for policy measures” for population problems if it did not have a permanent research institution supplying up-to-date data and analysis.Footnote ¹¹⁶ It also stressed the advantage of a permanent institution from the international viewpoint. An official institution, according to the resolution, would act as a collaborative partner internationally, liaising between the Japanese government and international population organizations, such as the International Union for the Scientific Investigation of Population Problems (est. 1928) that was a result of the World Population Conference.

The government initially took up the resolution and secured a budget to set up a permanent population research institute for the 1931 financial year. However, the plan fell through due to the cabinet’s resignation on April 13, 1931 after Prime Minister Hamaguchi Osachi was shot.Footnote ¹¹⁷ Nevertheless, the IC-PFP’s call was not entirely futile. It eventually led to the establishment of the Foundation-Institute for Research of Population Problems (Zaidan Jinkō Mondai Kenkyūkai, hereafter IRPP) on November 22, 1932. Though not directly a government body, in many ways the IRPP was a successor organization to the IC-PFP Population Section, de facto acting as a policy research institute and a government inquiry body on population matters.Footnote ¹¹⁸ The Population Section’s campaign in the late 1920s laid a foundation for establishing an institution specialized in policy-relevant population discussion and research.

In addition to lobbying for a permanent research institute, the Population Section itself contributed to the policy-oriented research on population problems. Specifically, the Home Ministry Bureau of Social Affairs conducted birth control research during the policy deliberation process. The study not only supplied materials for discussion to the Population Section but significantly also buttressed the official policy on birth control in later years.

The Home Ministry Bureau of Social Affairs began investigations on birth control in 1922 – upon Sanger’s visit to the country.Footnote ¹¹⁹ However, the work conducted at the time concentrated on the collection and analysis of publications on birth control.Footnote ¹²⁰ In the late 1920s, for a policy deliberation within the IC-PFP, the Bureau of Social Affairs conducted a more thorough investigation. First, it prepared a reference list on birth control research that had been conducted internally. The list, dated January 1928, was used by Bureau of Social Affairs Secretary Kawanishi when he presented at the Population Section Special Committee meeting on July 13, 1928, which brought up birth control and eugenics for discussion for the first time within the Population Section.Footnote ¹²¹

Along with this, Bureau of Social Affairs bureaucrat Masuda Shigeki conducted research on the birth control movement that justified why the Bureau of Social Affairs had recommended birth control research in its draft of the IC-PFP Secretariat’s reference plan. Masuda, who had long engaged with population issues for his work on social work and labor policies, adopted eclectic approaches to the topic. For the internal classified report, “An Investigation on Birth Control,” dated February 1928, Masuda first conducted a review of the world history of “modern thoughts regarding birth control,” starting from the publication of Thomas Malthus’s An Essay on the Principle of Population in 1798, and studied the evolution of birth control movements in Britain, the United States, Holland, and Norway, as well as international movements since the mid-nineteenth century.Footnote ¹²² He then gathered information on the popular birth control movement in Japan since Sanger’s visit in 1922. He collected names, addresses, and the details of the services provided by individuals running birth control clinics and selling birth control products, including abortifacients, in the cities of Tokyo, Osaka, Chiba, Nagoya, and Kobe, as well as in Chiba and Shizuoka Prefectures. Additionally, Masuda examined various birth control methods, including surgical methods such as hysterectomy. Based on the report, Masuda explained the situation surrounding birth control at the meeting of the Population Section Special Committee on July 13, 1928, standing next to his boss, Kawanishi.Footnote ¹²³

Masuda’s report generally maintained a neutral take on birth control, concentrating mostly on giving the factual data he had gathered through his investigation. Yet, from time to time, certain views shaped the report, especially when he gave analysis and policy recommendations. Of these, one echoed the concern over “reverse selection” addressed by Nagai Hisomu. Elaborating on the argument in favor of birth control from the viewpoint of population problems, Masuda warned that officials in Japan would have to consider the following two points if they were planning to endorse birth control policies: (1) “the fact that the birth rate is declining among the upper class,” and (2) “the [fact that] population growth … refers to the drastic growth of the people in low classes.”Footnote ¹²⁴ Following this comment, Masuda showed statistical data on fertility among different social groups in Japan, such as the table showing the number of births per every thousand in the “rich” and “poor” areas within Tokyo’s Yotsuya-Ward, and suggested that a process of “reverse selection” had a jumpstart in Japan, at least in cities.Footnote ¹²⁵

In conjunction with this, Masuda introduced the birth control initiative in Holland as an example of a successful state-led birth control campaign. He praised the initiative for not only “decreas[ing] the mortality and infant mortality rates significantly” but for also making the rate of natural population growth in Holland “one of the best in the world,” thus projecting the message that a birth control initiative with a strong government presence could tactfully adjust the population size and quality to an optimal state.Footnote ¹²⁶ Based on this information, he made five recommendations toward the end of the report, which included government leadership in “the establishment of a consultation clinic catering to the women of the lower class and poverty class with many children who, because of their situations, wish to practice birth control.”Footnote ¹²⁷ The report clearly projected the view that a government-led birth control program was integral to social work and that specifically targeting the lower classes would adequately circumvent the process of “reverse selection.”

Though produced by a mid-rank bureaucrat, Masuda’s report had a lasting impact on the government’s attitude toward birth control.Footnote ¹²⁸ It not only underpinned the official discourse on the subject but also provided a blueprint for the government’s birth control policy.Footnote ¹²⁹ The aforementioned Population Section Small Committee dedicated to population control decided to incorporate two of the policy recommendations presented in Masuda’s report which recommended, respectively, that the government should “establish appropriate institutions enabling consultations on marriage, childbirth, and birth control” and “enforce control over distribution, sales, and advertisement for instruments, pharmaceuticals, and other materials assisting contraception.”Footnote ¹³⁰ Of these, the latter was taken up by the Special Committee on Racial Hygiene (Minzoku Eisei nikansuru Tokubetsu Iinkai), established on June 24, 1930 within the HHSG following the dissolution of the IC-PFP in April 1930. This special committee – which Nagai Hisomu was instrumental in founding – submitted a draft proposal calling for the control of “harmful” (yūgai) contraceptives.Footnote ¹³¹ The Home Ministry adopted the proposal and issued the Ordinance for the Control of Harmful Contraceptive Devices on December 27, 1930 as Ministerial Ordinance No. 40 (enacted on January 6, 1931).Footnote ¹³² Following Masuda’s original report, the ministerial ordinance defined harmful contraceptive devices to include “contraceptive pins,” and “other contraceptives designated by the home minister to cause harm from the viewpoint of hygiene.” In the 1930s, Masuda’s report set the tone for the official attitude toward birth control as a population measure at a time when population became redefined as a valuable resource to be mobilized for Japan’s engagement in a total war.

Conclusion

In the 1920s, with the increased availability of demographic data, “population problems” became a topic of public discussion. The heightened public interest in “population problems” exhibited an emerging consensus that a distorted population trend could be a source of economic, political, and social problems. High-rank bureaucrats and politicians followed public debate’s logic. They portrayed “population problems” as dovetailing with a wide range of interlinked issues, such as food, industry, employment, poverty, space, and race, and thought they should be tackled with government policies.Footnote ¹³³ Through public and policy discussions, “population problems” became shorthand for a myriad of issues associated with the population trend that were subjected to government intervention.

The establishment of the IC-PFP as the first-ever official research committee specializing in population matters in this context symbolized the burgeoning of a new mode of interplay between science and the governing of Japan’s population. It was set in motion by the belief that rational population management required government policies as well as an independent institution dedicated to policy discussion and research. Reflecting the all-encompassing concept of “population problems,” the IC-PFP singlehandedly took charge of coordinating policy-oriented population research under one roof. Yet, recognizing that the population problems required intervention from many disciplinary angles, the IC-PFP also summoned population experts from diverse medical and scientific fields. As a consequence, the IC-PFP – reifying the government’s commitment to solving “population problems” through policies – helped foster population research as an institutionally-based, multidisciplinary endeavor. It also produced a new kind of population specialists, an amorphous community of bureaucrats, scientists, and medical researchers acting as policy experts, who were united by the effort to conduct policy-oriented population research and to advise the government on population issues based on the research.

Overall, the new mode of science-governing interplay built around the IC-PFP was productive. The population research conducted under the aegis of the IC-PFP directly fed policy discussion, which then yielded policy recommendations on the topics initially raised by the government. Yet, the actual deliberation process also highlighted elements of discord in this relationship, as exhibited in the discussions on birth control, eugenics, and population control within the IC-PFP Secretariat and the Population Section. But, the dissonance did not automatically mean this interplay was unproductive. In the 1930s, as Japan’s entry into total war heightened official interests in eugenic population management, “On Various Measures for Population Control” made a significant mark in history.Footnote ¹³⁴ It paved the way for institutionalizing eugenic and social policy measures with a specific aim to “improve” the quality of the Japanese race and population. From the government’s point of view, even the elements of discord yielded a productive outcome.

The 1930s saw the rise of another conception of population – as a “resource” – which in turn shaped the official narrative. Amid total war, the policy agenda informed by this understanding addressed issues of population quantity, quality, and movement, but specifically focused on the relationship between people and the intangible yet emotionally charged concept of “national land” (kokudo).