Birth control survey research, technical bureaucrats and the imagining of Japan’s population, 1945–60

Abstract This article explores a birth control survey conducted by the Japanese government between 1945–1960, and analyses how this research, both as scientific practice and knowledge, resonated with government efforts to manage the population during post-war reconstruction. Focusing on Shinozaki Nobuo, a Ministry of Health and Welfare ‘technical bureaucrat’ (gijutsu kanryō or gikan) specializing in population issues, this article depicts how human agency participated in the at times precarious relationship between policy and practice. It also explores how the epistemological framework inscribed in the resulting scientific knowledge harmonized with the economic and political rationale supporting post-war reconstruction. This article contributes to the study of modern Japan by highlighting the critical, yet thus far underexamined role that population science and technical bureaucrats played in Japanese statecraft. At the same time, it demonstrates that the interaction between state governance of population and the creation of scientific knowledge about the populace was fundamentally complex.


Introduction
Imagine it is 1947. You are a married woman in your thirties and your husband is a factory worker employed by Ajinomoto, a renowned Japanese company manufacturing monosodium glutamate seasoning. In all likelihood, your husband will be given a survey questionnaire from the Ministry of Health and Welfare Institute of Population Problems (IPP) entitled 'Birth Control Research Card', asking you and your husband to provide details about your experiences of and general opinions on birth control (K oseish o Jink o Mondai Kenky usho 1947).
In the decade following this pilot survey, Japan witnessed what might be termed a birth control survey boom. This boom, on the one hand, was supported by the media. In response to perceived 'overpopulation' (kaj o jink o) caused by mass repatriation and a post-war baby boom, the Mainichi Newspaper, for instance, set up an in-house research group specializing in population issues and organized its own birth control survey. On the other, the government also played a pivotal role in this boom. In response to policy debates about the possible implementation of birth control as population management, the Ministry of Health and Welfare ordered the IPP to conduct birth control surveys. These provided material for further debate, leading to a Cabinet decision to make birth control a national policy in 1951 and the official announcement in 1954 that birth control was to be regarded as a population control measure. This birth control survey boom continued until the late 1950s, when birth rates plummeted.
This article examines this explosion of birth control surveys, particularly the official surveys led by Shinozaki Nobuo (1914, the IPP technical bureaucrat charged with population issues. This focus will illustrate the political nature of the official birth control survey as a social survey. Having studied what contemporaries termed the 'social survey movement' in China during the Republican era, historian Tong Lam has suggested that social survey is best understood as a 'political practice' and a 'mode of knowledge production', and was directly linked to the transformation of China from a dynastic empire to a modern nation state (Lam 2011, 2-3). Similarly, post-war Japan's official birth control survey acted as a political tool. This research clarified the patterns of people's reproductive and sexual lives as well as the influence of these patterns on demographic trends, and in so doing, provided exactly the type of knowledge the government needed to govern the Japanese population amidst the drastic political changes following the Asia Pacific War. At the same time, the knowledge produced by the survey projected an image of the Japanese population, which was highly important in the country's post-war struggles to rebrand its political identity from the ruler of Asia's multi-ethnic empire to an ethnically contained nation state in East Asia (Kushner and Muminov 2017;Asano 2013). The survey research contributed to post-war Japan's political project doubly, firstly by providing a set of data that characterized human reproduction as a phenomenon that could be politically engineered, and secondly, by inscribing knowledge about the Japanese population that served to stabilize the political process of demarcating the 'boundaries of the Japanese' (Oguma 1998).
This article examines the type of political dynamics that shaped official birth control surveying. First, I will depict how the surveys thrived in the specific political context of post-war Japan, where 'overpopulation' was viewed as a source of social problems directly affecting Japan's economic future, leading to calls for official intervention. Then, I will examine the role of Shinozaki as a technical bureaucrat in the creation of the birth control survey research that supported government policy. The Japanese term for technical bureaucrat, gijutsu kanry o or gikan, which Hiromi Mizuno has translated as 'technologybureaucrat ' (2009, 20), was the official title for bureaucrats who served the government through their technical expertise. Although often used synonymously with the English term 'technocrat', the Japanese term illustrates the specific historical context of modern Japan. The category emerged in the Meiji period, a time when the new government's commitment to building a modern nation state and empire with technologically enhanced industry and military, instigated the training of technically competent bureaucrats (Kashihara 2018). During the Asia Pacific War, gijutsu kanry o strove to establish their identity in state politics by stressing their role as vanguards of cutting-edge techno-science, and by promising to ensure the Japanese Empire's self-sufficiency through their involvement in the scientifically-informed, rational distribution of natural resources, labor and capital (Aaron Stephen Moore 2013;Mimura 2011;Mizuno 2009, 19-68;Oyodo 1997). Studies have depicted gijutsu kanry o as elite career bureaucrats, whose positions were upheld by a trust in technoscience's ability to rationally manage and control culture, economy and society for national prosperity, but who were ultimately compelled to negotiate with other stakeholders to assert their position within the larger socio-political context (Mimura 2011;Hein 2004).
Drawing on this earlier work, this article examines Shinozaki as a representative of the less studied group of social scientific and medical gijutsu kanry o specializing in human reproduction for population policy, and considers how they aspired to contribute to statecraft by participating in the government-led population governance exercise through application of their technical expertise on public health, human sciences or social policy. At the same time, this article will further scholarship by highlighting the attributes of these technical bureaucrats as bearers of medico-scientific knowledge. I will argue that the day-to-day practices of these technical bureaucrats hinged on their often blurred identities as scholars and administrators. This blurring facilitated three intertwined developments; (1) the production of policy-oriented scientific knowledge about Japan's population, (2) the creation of the field of population science specialising in the relationship between reproductive behaviours and demographic trends, and (3) the introduction of administrative tools allowing the governance of population via fertility regulation.
A focus on population bureaucrats to analyze statecraft in modern Japan is advantageous for the following two reasons. Firstly, due to the bureaucrats' proximity to state efforts to manage the population (Ogino 2008b;Tama 2006), their research practices effectively reveal the types of scientific knowledge prioritized by the state, while also illustrating efforts made by the technical bureaucrats themselves to make the reproductive experience of the governed population 'legible' for the state (Scott 1998). Secondly, studying technocrats, who Eva E. Buckley has characterized as 'middle points' liaising between various policy stakeholders (Buckley 2017), enables us to illuminate human factors that shaped the state management of population and the supporting scientific knowledge. Shinozaki's dedication to birth control research was in part shaped by his own aspirations to establish population science. Yet, the research was not always successful: at times respondents would not cooperate, thereby compromising results. By addressing these human factors, this article presents a more nuanced history of state population governance than is provided by most accounts.
This article will also clarify the political vectors that informed the specific ways in which the survey data on the opinions and experiences of research participants' reproductive lives was presented. In so doing, I pay particular attention to two conspicuous phenomena within the process: (1) the evident absence of a race category in the survey research, despite the pervasiveness of race in Japanese population discourse of the time (Roebuck 2015(Roebuck , 103-184, 2016, and (2) the categorization of data by region and socioeconomic status. I argue that these phenomena were not accidental, but rather, indicate the participation of specific politics. Firstly, by not addressing race, this research crystallized the image of an ethnically homogeneous Japan that was becoming an increasingly dominant concept. Secondly, the explicit focus on certain socioeconomic and regional categories reveals post-war Japan's approach to what Michelle Murphy has termed the 'economization of life', a 'historically specific and polyvalent mode for knitting living-being to economy' (Murphy 2017, 13). Although the association of human 'reproduction' (seishoku) with economic 'reproduction' (saiseisan) was not novel in post-war Japan (Lee 2017), an additional way of 'knitting living-being to economy' appeared in population discourse during this period, as scholars adopted what is now commonly known as the 'demographic transition model'. Viewing certain reproductive patterns as signs of progress, the demographic transition model aligned countries in a hierarchical order on the spectrum of socioeconomic development. In the midtwentieth century, this model provided a fundamental premise for the transnational population control movement, by providing metrics to determine which countries required reproductive intervention for socioeconomic development. However, when this logic was applied to post-war Japanese birth control research, it stimulated an introspective perspective focusing on regional and socioeconomic categories within Japan, the categories essential for measuring post-war Japan's economic achievements. This perspective, when combined with the assumed ethnic homogeneity of research participants, led to the prioritization of internal social orders over racial hierarchies in the analysis of birth control behaviors. In other words, the notion of Japan's ethnically homogenous population together with the developmentalist logic that explicitly encouraged a domestic socioeconomic hierarchy, served to produce specific knowledge of the population: that is, knowledge that was particularly compatible with post-war Japan's reconstruction efforts.
With these points in mind, firstly, I examine how the discourse of 'overpopulation' immediately following the Asia Pacific War eventually led to the issuing of a government birth control policy in 1951. I then discuss Shinozaki's role in the policymaking process and the related research. Finally, I will show how the specific perspective adopted for the presentation of survey data championed state efforts to govern the population for the sake of national reconstruction via economic development.
The discourse of overpopulation and birth control policy during and after the occupation Population growth was the subject of policy debates in Japan from the 1920s (Lee 2017;Sugita 2010Sugita , 2013Fujime 1997, 245-281;Tipton 1994Tipton , 1997 until the outbreak of the Asia Pacific War, at which time the government began to endorse pronatalism (Fujino 2003). Policy debate on 'overpopulation' as a 'population problem' (jink o mondai) emerged as the populace expanded by eight million in the years following Japan's surrender in August 1945, through rising birth rates and an influx of repatriates (Ogino 2008a;Norgren 2001;Oakley 1978).
While agreeing with the argument in principle, commentators differed on what exactly constituted the 'problem' in ways that reflected their disciplinary backgrounds. Those with an inclination to Malthusianism focused on already evident food shortages and future land erosion (Dinmore 2006, 111-136). Economists argued that 'overpopulation' would cause mass unemployment and distort the distribution of populations to the various industrial sectors, thereby impeding state efforts to reindustrialize (Tachi 1950). Medical experts tended to claim overpopulation was in part caused by effective 'death control': the decline in mortality rates due to improved public health (Homei 2016a;Sams 1998). Those with eugenic tendencies raised concerns that overpopulation, if unchecked, would trigger 'reverse selection' (gyaku t ota) -the domination of those with 'inferior' biological traits over 'superior' individuals -and ultimately 'lower' the quality of the Japanese population as a racial group (Matsubara 1998, 91-92). Despite these diverse interpretations, one issue gained unanimous support: 'overpopulation' would impede state efforts to reconstruct their war-obliterated nation.
Beyond government circles, birth control activists were fervently discussing population dynamics (Takeuchi-Demirci 2018). Neo-Malthusians claimed overpopulation would exacerbate poverty, while socialists argued it would benefit exploitative capitalists by generating surplus labor (Ogino 2008b, 152-154). Kat o Shizue, a leading figure in popular birth control activism since the 1920s (Takeuchi-Demirci 2018Hopper 1996), articulated overpopulation in terms of the challenges Japanese women confronted in their everyday lives (Hopper 1996, 175-250). For activists struggling to rebuild their movement after government suppression, the narrative of overpopulation provided an impetus to relate their raison d'être to state reconstruction.
Under the US-dominated Allied Occupation (1945)(1946)(1947)(1948)(1949)(1950)(1951)(1952), 'overpopulation' also rapidly became a priority within the Supreme Commander for Allied Powers General Headquarters (SCAP-GHQ) (Oakley 1978). Officials within SCAP-GHQ were concerned about a potential negative impact on the Occupation's most important mission: the transformation of Japan into an independent sovereign state (Dinmore 2006, 111-159). Due to shortages, Japan had relied on US food aid since the onset of the Occupation (Fuchs 2007), and more mouths to feed would hinder progress toward national independence (Dinmore 2006, 133). The SCAP-GHQ personnel were also concerned that overpopulation would hamper their efforts to reindustrialize and revitalize the capitalist economy. Finally, the idea that 'overpopulation' would lower living standards and lead to political instability was a source of concern within SCAP-GHQ in light of the escalating Cold War. As overpopulation was understood to intersect with the wide-ranging issues of food, land, labor, health and security, various officers within SCAP-GHQ engaged with the issue.
The narrative of population crisis prompted the Japanese government and SCAP-GHQ to build an institutional infrastructure to tackle the problem (Sugita 2019, 4-7). Within SCAP-GHQ, officers and consultants in the Public Health and Welfare Section (PH&W) and Natural Resources Section (NRS) held various conferences on the issue (Oakley 1978). Within the Japanese government, IPP was reinstalled as early as May 1946, as the official research organization to assist the Ministry of Health and Welfare (MHW), charged with population issues ('Manual of the Institute of Population Problem' 1951). The government also advised that the semi-governmental Foundation-Institute for Research of Population Problems (IRPP), dormant during wartime, resume its activities. In April 1946, the IRPP set up a Committee on Population Measures (IRPP-CPM) to be solely dedicated to deliberation of population policies (Sugita 2019, 6), and in April 1949, the government founded the Advisory Council on Population Problems (ACPP) within the Cabinet. From that time forward, these three organizations -IPP, IRPP and ACPP -established a collaborative relationship so tightknit that social policy expert Nagai T oru -a leading figure in the structure -described it as a 'trinity for the deliberation of population issues' in post-war Japan (Sugita 2010, 207). According to the model, the IPP would conduct research and generate data on population, the IRPP would deliberate over population issues using IPP data and submit draft recommendations to the ACPP, and finally, the ACPP would deliberate and submit resolutions to the government (Sugita 2010, 204). Over the 1950s, this 'trinity' system was established as a mechanism for the creation of population policies (Sugita 2010, 207).
Birth control -often used synonymously with 'family planning' (kazoku keikaku) -was a key population policy the 'trinity' enthusiastically pursued during the 1950s. 1 Before and during the war, official discourse on birth control -in the form of contraception -was largely negative, reflecting the fact the majority of policy intellectuals were concerned about 'reverse selection'. Birth control also had a bad reputation within the government, since popular birth control activism was associated with socialist, feminist, and labor movements, all of which were viewed by conservative politicians and state officials as propagating dangerous foreign ideas (Takeuchi-Demirci 2010). Birth control became viewed more favorably when it was realized the 1949 amendment of the Eugenic Protection Law (EPL, established in 1948 based on the wartime National Eugenic Law), permitting women to have abortion for economic reasons, had led to rising abortion rates. Viewing this as a public health crisis, technical bureaucrat Koya Yoshio (1890-1974, head of the Institute of Public Health and a member of the ACPP, approached the Minister of Health and Welfare, Hashimoto Ry ogo, and urged him to consider birth control policy as a solution to abortion (Koya 1950, 2). Koya's campaign ultimately led to the 'trinity' debating the possibility of birth control measures (Koya 1951, 2).
Following these 'trinity' deliberations, on 26 October 1951, the Cabinet decided to popularize birth control throughout the country, with the MHW responsible for implementation. In 1952, the EPL was amended to accommodate the new policy (Tama 2001;Norgren 2001;Matsubara 1998), and the Eugenic Marriage Consultation Centers based within local health offices charged with providing guidance on birth control to married couples. The amendment also created a new category of healthcare professionals: 'birth control field instructors' (jutai ch osetsu jicchi shid oin) (Kimura 2013;Obayashi 1989). Recruited primarily from the pool of midwives and public health nurses, 'birth control field instructors' were expected to hold seminars on birth control and distribute contraceptives to married couples in their communities at wholesale prices. Recommendations by the 'trinity' mobilized central and local government health agencies to organize activities to disseminate the knowledge and practice of birth control across the country (Homei 2016b). 2 The process of establishing government birth control policy illustrates how various assertions about the 'population problem' prompted the state to attempt to discipline reproductive bodies through policy. In the specific context of post-war Japan, the eagerness for national reconstruction, fueled by a sense of demographic crisis, bolstered state efforts. Yet, the 'state' itself had little power, and had to rely on the support of entrusted state actors, including the technical bureaucrats.

The role of technocrats in birth control policy
As soon as the 'population problem' arrived on the political agenda during the 1920s, population experts assuming the positions of technical bureaucrats began contributing to the creation of population policies by promoting and conducting population research (Sugita 2010(Sugita , 2013. Originally, few took part in the actual implementation of measures, but with a post-war birth control policy that required concrete initiatives, a number of technical bureaucrats eagerly undertook more practical roles.
The activities of Koya, one such technical bureaucrat, have been widely documented (Takeuchi-Demirci 2018; Homei 2016a, 2016b; Toyoda 2010). Less known but equally important was Shinozaki Nobuo (Okazaki 1999). Shinozaki was among the first graduates of anthropology at the University of Tokyo after Hasebe Kotondo (1882Kotondo ( -1969 founded the Department of Anthropology in 1939. Following graduation, he remained in the Department as Assistant Professor until June 1943, when he became Koya's colleague at the Ministry of Health and Welfare Research Institute Department of Population and Race. Shinozaki shared many interests with Koya, having carried out work on such issues as miscegenation and the link between racial characteristics and environment during the war (Shinozaki 1943(Shinozaki , 1944. After the war, as a mid-career IPP bureaucrat, Shinozaki assumed an important position within the 'trinity' as Secretary for the IRPP-CPM's Second Sectional Meeting and began to explore the possibility of adjusting population quantity and quality. Shinozaki became interested in birth control sometime in the late 1940s and early 1950s, having observed women resorting to abortion to limit family size, which appeared to be impacting population trends (K oseish o Jink o Mondai Kenky usho 1951). Shinozaki lamented that many women were practicing abortion under the erroneous assumption that 'abortion and infanticide of the Tokugawa era' was 'modern birth control'. In Shinozaki's view, 'modern birth control' referred to rationally planned, proactive contraceptive practices based on scientific principles, rather than the retroactive measures of abortion and infanticide to counteract unplanned conception. Shinozaki further argued that 'modern birth control' would directly assist official efforts to build a modern, rational and democratic society by creating a suitably disciplined family (Nobuo Shinozaki and Aoki 1959). Based on this rationale, he claimed education about 'modern birth control', embedded in an 'active effort to rationalize and improve life', was urgently needed (K oseish o jink o mondai kenky usho 1949, 23), and was thus committed to realizing this through government birth control policy.
From the 1950s on, Shinozaki made every effort to implement birth control programs as part of government policy. To establish these programs he joined forces with the post-war New Life Movement, a half-state, half-private initiative intended to promote a democratic, efficient and cultured life by rationalizing everyday activities (Ogino 2008b, 208-213;Tama 2006, 100-161;Gordon 2005;Takeda 2005, 127-152). This ethos resonated perfectly with his concept of 'modern birth control', and the private-government partnership would make it easier for him to gain support. Shinozaki believed disciplined families with fewer children, attained through 'modern birth control', would produce financial benefits for both government and private organizations -the government would save on child welfare costs while companies would pay less for benefit packages -and this could prove a powerful incentive for widespread support (Gordon 2005;Obayashi 1989, 210). 3 Between December 1954 and September 1957, Shinozaki and his colleagues championed these plans to over 140 companies and chambers of commerce (Tama 2006, 107-108). Once the New Life Movement family planning program had been launched, Shinozaki organized a national council of private corporations to facilitate communication between company representatives (Tama 2006, 118-119). He also liaised between the MHW's Department of Welfare and private corporations to ensure the program's smooth operation. By 1958, in part due to Shinozaki's activities, 83 public and private corporations had launched or begun to prepare in-house family planning programs (Tama 2006, 110-111).
Thus, Shinozaki was instrumental in the initiatives underpinning official birth control policy. He took advantage of his position within government to influence policymaking and implement policy by liaising between government officials and other stakeholders, thereby reducing the distance between the government and the governed, and facilitating state efforts to manage the population.
It must be emphasized that this dedication to state-endorsed birth control initiatives was not the automatic result of his role as a state bureaucrat; Shinozaki's attributes as an expert in the field of racial and demographic sciences were equally critical in motivating his leadership of government birth control policy. In the late 1940s, while working on the aforementioned birth control campaign, Shinozaki, along with Koya and other colleagues, established a society for population scientists specializing in the correlation between reproductive and demographic behaviors. Thanks to Shinozaki's effort, the Population Association of Japan (PAJ) was founded on 11 November 1948, the first professional organization in Japan dedicated to the advancement of demographic studies (Nihon jink o gakkai s oritsu 50-sh unen kinen jigy o iinkai 2002,9). Together with Koya, Shinozaki also helped the PAJ expand by recruiting colleagues who were conducting applied demographic research for birth control policy. Shinozaki's birth control work as a state official and his science-building activities were tightly enmeshed, and it was the manner in which the science-making was coproduced with policymaking that explained his commitment to birth control.
These attributes of technical bureaucrats such as Shinozaki -not just government bureaucrats but bureaucrats with scientific expertise -are significant when reflecting on their unique contribution to statecraft. Through their daily activities, technical bureaucrats also produced knowledge that would become a fundamental basis for national policy. Shinozaki, tasked with providing data with which to produce a national population policy, was responsible for the majority of IPP birth control surveys. To construct a 'national' picture of birth control practices he conducted research in as many regions as possible: Shinozaki's survey team visited 17 prefectures between 1951 and 1952, collecting data from a total of 44,509 individuals (K oseish o Jink o mondai kenky usho 1952).

Shinozaki and birth control research
Alongside his official obligations, Shinozaki's enthusiasm for this work also came from his belief it would validate the corporate-based New Life Movement campaign (Nobuo Shinozaki 1952) 4 Therefore, the research he conducted was often targeted at workers. The pilot survey introduced at the beginning of this article recruited from staff at the University of Tokyo's School of Medicine, the Japan Steel Pipe Company (Nihon Kokan), Fuji Electronics Appliances Company, the MHW and the Tokyo Metropolitan Government, in addition to the Ajinomoto Company (Nobuo Shinozaki 1947). These surveys were designed by Shinozaki and intended to develop an official understanding of public opinion of birth control.
Data was collected through questionnaires and interviews. Questionnaires were mainly multiple-choice, inviting respondents to tick the one or more boxes they deemed closest to their answers. For the question, 'Why have you not practiced birth control?', for example, the questionnaires provided the following options: '(1) Because I do not know about contraception (2) Because I feel it is a burden (3) Because I do not like it (4) Because either a husband or a wife is infertile' (Nobuo Shinozaki, Kaneko, and Kobayashi n.d., 4) The interview that typically followed was intended to fill gaps in the knowledge gained from questionnaires. Often conducted by a fieldworker at a respondent's home, these included intimate details about sexual behavior as well as opinions on contraception (Shinozaki 1949).
For the most part, Shinozaki's team reported the survey results in the form of numerical data, categorized by the respondents' personal attributes. For instance, in the survey of birth control practices in the Tokyo suburbs of Musashino City, Abiko Town, Tanaka Village, Tomise Village and Kobari Village, the team would first calculate the actual number and percentage of 'practitioners' against the total populations of the five administrative units -361 (43.1%), 218 (15.3%), 52 (6.9%) 76 (12.3%) 9 (3.7%) -then catalogue the data according to husband's occupation and level of education, wife's age and occupation, duration of marriage, number of children and finally, the amount of cultivated land (Nobuo Shinozaki 1952). The assumption was that this way of displaying numerical data would accurately reveal not only the opinions of respondents, but also the 'actual state of the spread of birth-control', as expressed in the title of the survey research.
The survey was conducted on the premise that collecting respondents' opinions on the 'actual state' (jittai) of their reproductive and sexual lives would facilitate the creation of successful policies (Nobuo Shinozaki 1952). This assumption needs unpacking: how could the opinion of birth control itself contribute to government efforts to govern Japan's population? Koyama Eiz o, first director of the National Public Opinion Research Institute and a former colleague of Shinozaki at IPP during the war, held ideas that help us address this question (Morris-Suzuki 2000). According to Tessa Morris-Suzuki, Koyama contended that opinion research never simply mirrored the mood of the general public but was rather a force in itself, shaping the current of mainstream opinion. Koyama further argued that the role of government in this situation was that of a doctor; coordinating opinions based on research results, and intervening if attitudes revealed 'maladies' (Morris-Suzuki 2000, 515). Faith in the corrective power of knowledge produced by their surveys was widely shared by IPP officials, who believed their research into public opinions on family size and ideal contraception practices would be utilized by the government to influence reproductive behaviors as required. Birth control surveys thus enjoyed a special status within the state, in part because of the certainty that public opinion could be utilized as a tool of governance.
Despite this confidence, Shinozaki's fieldwork faltered when research subjects refused to cooperate. For instance, in 1949For instance, in -1950, when Shinozaki's survey team conducted fieldwork in Aomori, Iwate and Miyagi Prefectures, as many as 2073 married couples either did not return the questionnaire or returned it incomplete (K oseish o jink o mondai kenky usho 1951). Further investigation revealed that 455 of these couples had found the questionnaire too difficult to understand, eighty-five could not be bothered to fill it in, and a small number stated they were simply 'not interested' or 'did not like to be asked such questions'. Confronted with these findings, Shinozaki became 'acutely aware of the need to make questions easier', but was also resigned to the fact that some people would always be unwilling to share personal information (K oseish o jink o mondai kenky usho 1951, 2-3). The survey's actual fieldwork thus required diplomacy and negotiation, and the scientific knowledge gleaned from such fieldwork could potentially detail only a partial picture of the 'actual state'.
Nevertheless, throughout the 1950s, Shinozaki tirelessly led survey research with the conviction that cumulative data on opinions of birth control on a regional level would eventually form a big picture, capturing what he termed the 'actual state of spread of birth-control' throughout Japan, and that this big picture would enable the government to effectively implement population policies (Nobuo Shinozaki 1952). His trust that scientific data could facilitate the governing of Japan's population reinforced his passion for the research.

Reimagining the Japanese population
In the context of post-war Japan, when the idea of 'Japan's population' itself was in flux, Shinozaki's research served the state in more ways than simply creating knowledge about reproductive bodies. Since it clarified patterns of reproductive behaviors that would directly inform the future profile of population dynamics, Shinozaki's surveying participated in a broader bureaucratic activity of compiling demographic data to establish a new interpretation of the Japanese population.
Immediately after the war, scientific investigations to collect numerical facts about the population emerged as a major bureaucratic objective in Japan. Following surrender, the Japanese Empire collapsed almost overnight, triggering territorial disputes and mass migration on a scale not witnessed in the previous era (Xu Lu 2019;Iacobelli 2017;Igarashi 2016;Araragi 2011Araragi , 2013Watt 2009). Migrations and shifting national borders challenged the existing notion of the 'Japanese population' that had held currency under colonial rule (Shiode 2015;Morris-Suzuki 2010;Oguma 1998;Watt 2009). For both the Japanese state and Occupation governments, this was highly problematic: various factors shaping sovereignty, such as citizenship and land ownership, relied on this destabilized category (Morris-Suzuki 2015;Endo 2013;Chapman 2011;Michiba 2002). Under these circumstances, examination of the Japanese population became a priority.
Thus, government offices swiftly began to compile population statistics. Censuses were carried out by SCAP-GHQ six times between September 1945and October 1950(Oakley 1978, and the Japanese government's IPP and Cabinet Bureau of Statistics were assigned similar tasks ('Chikaki sh orai naichi (hokkaido, honshu, shikoku oyobi kyushu) nioite fuy o subeki jink o no suikei' 1945). The actual processes of collecting and presenting demographic data were complex, indicating how much effort population bureaucrats made to stabilize knowledge of the Japanese population (K oseish o kenky usho jink o minzokubu 1945). Constant adjustments were required when calculating demographic data to accommodate ongoing political changes (S omush o T okeikyoku 2019).
For technical bureaucrats in charge of compiling population figures, this kind of adjustment was a standard administrative task. Yet, in the specific context of post-war Japan, it was simultaneously more than just routine work: these endeavors were intimately interacting with the process of redrawing the boundaries of Japanese citizenship. As Tessa Morris-Suzuki has described, the making of post-war Japanese citizenship was predicated on the marginalization of various groups, not least former colonial subjects, who were now given the political status of what she has termed 'semi-citizenship' (Morris-Suzuki 2015). To conform to this legal practice, the compilation of population statistics required constant negotiations over who should be included in, or expunged from, the category of Japanese. Through the adjustment work of technical bureaucrats, the population of Japan would soon be repackaged as a historically consistent, ethnically homogenous, national group in accord with the new political outline of the Japanese state.
Similarly, Shinozaki's research portraying the individuals reproducing the future Japanese population also contributed to the image of ethnically homogenous Japanese nationals. However, in contrast to the census work, which categorized various constituents of the former empire along ethnic and territorial lines, the birth control research confirmed this image by presenting ethnicity as a non-issue: generally silent on the racial identity of research participants, the surveys suggested this was self-evident. On the odd occasion that race was mentioned it was depicted as a foreign phenomenon. For instance, one of Shinozaki's surveys introduced a table showing ethnicity -'black' and 'white'as a factor in the correlation between pregnancy rates and socioeconomic class, but this was simply a citation from research conducted in the United States (Nobuo Shinozaki 1947). As the table was for reference only, the impression was given that ethnicity was tangential to reflections on Japanese demographic phenomena. By presenting race in this manner, the research projected a message that was then flourishing in official discourse: only reproduction by ethnic Japanese people should count in the reconstruction of Japan as a nation.
In reality, the boundary of the Japanese population during this period was far more contested than Shinozaki's research suggests, mirroring the reconfiguration of post-war Japan that Lori Watt once characterized as 'the uneven and incomplete process of absorbing and re-categorizing the fragments of empire within Japan' (Watt 2009, 5). Following the collapse of the Empire, Japanese citizens in the colonial metropole and soldiers at the front were redefined as 'Japanese population placed externally' (zaigai naichijin). Some repatriated to Japan, others stayed away. Among those who did not return were young women marrying into Chinese families, who became known as 'remaining women' (zanry u fujin), as well as adopted Japanese orphans, the 'children left behind in China' (ch ugoku zanry u koji). While the majority of the 700,000 Koreans forcibly migrated to Japan during the war were repatriated to the Korean Peninsula after 1945, those who stayed in Japan became known as Zainichi Koreans (Araragi 2017;Asano and Asano 2013). Furthermore, with the advent of the US Occupation, the people of Okinawa were now legally called Ryukyuans and declared 'foreigners' along with former Korean, Chinese and Formosan colonial subjects (Shiode 2015, 351-411). Finally, immediately after Occupation, the Japanese press declared a state of national crisis over the existence of orphaned 'mixed-blood children' (konketsuji) (Shimoji 2018, 61-133;Kamita 2018;Roebuck 2016). Whether these groups belonged to the Japanese population and what criteria should be used to determine eligibility were thorny issues for policymakers and technocrats specializing in population.
It was against this backdrop that Shinozaki's policy-oriented survey research attempted to uncover the 'actual state' of Japanese people's birth control practices. In a context in which the definition of Japanese population itself remained uncertain, the quantification of reproductive experience was not simply a mathematical practice; it also intersected with the question of how to recognize the Japanese population in the face of the shifting geopolitical map of East Asia. The birth control research engaged with this issue primarily by maintaining silence on the issue of race. This act of silence, I argue, ultimately served to stabilize increasing official claims of Japan's ethno-national identity.
In addition, the birth control surveying adopted an extra framework that corresponded to the domestic goal of national reconstruction. As I will explain in the next section, this was an introspective perspective that compelled viewers to view the Japanese as a productive unit contributing to the reconstruction effort through economic means.
Designing a productive population for the nation's bright economic future If race was not a primary category for classifying participants in the birth control research, then what was? As suggested above, Shinozaki's survey employed sociological classifications and regional differences to explore demographic variations. The report submitted on the authority of the IPP on 1 February 1952, based on the survey research led by Shinozaki, also used these classifications. Firstly, the report -consisting mainly of numerical data presented in tablesclassified research participants into two categories, 'those practicing birth control' (jikk osha) and 'those who are not' (fujikk osha), and then by social and geographical categories. Social categories were husband's educational level and occupation; geographical categories were prefectures, then the subcategories of city, town, farming village, mountain village and fishing village (K oseish o Jink o mondai kenky usho 1952).
Why did the IPP adopt these categories? There is no doubt that disciplinary conventions played a role; it was a long established standard in social scientific studies to categorize data according to region and socioeconomic status. However, the fact that the IPP surveys prioritized these specific categories over other possibilities does merit attention.
To account for the inclusion of occupation and education level, Michelle Murphy's concept of the 'economization of life' is useful (Murphy 2017). Murphy uses this term to describe 'practices that differently value and govern life in terms of their ability to foster the macroeconomy of the nation-state' (2017,6). In post-war Japan, 'economization of life' acted as a guiding principle, especially in such programs as the New Life Movement, in which efforts to discipline reproductive bodies were articulated in relation to reconstructing the national economy. However, Murphy also claimed that this 'economization of life' had re-established race as a category, in order to determine which lives were worth reproducing. In the case of post-war Japan, at least in the domain engaging with population policies, race was associated less with the fostering of economy than with nationalism, in part due to the aforementioned assumption of ethnic homogeneity. I argue that, in this context, other kinds of social attributes, such as education and occupation, were regarded as more appropriately informative of an individual's economic value. The birth control research embodied this logic in post-war population management.
In parallel, the predominant demographic discourse at that time, which incorporated a progressivist narrative, acted as a crucial background for the omnipresence of regional categories in the IPP research. This discourse, embodied in the so-called demographic transition model, maintained that a correlation existed between fertility patterns and socioeconomic developments on a linear time scale (McCann 2017;Greenhalgh 2012;Szreter 1993). The model also embraced the modernization theory later associated with the economist Walt W. Rostow, which claimed demographic patterns universally shifted from a 'high-birth' 'high-death' to a 'low-birth' 'low-death' model as a society progressed from the 'pre-industrial' to 'post-industrial' stage. In the Cold War, this discourse was used to justify US family planning aid programs in 'underdeveloped' nations in order to establish a 'free-world' alliance (Sharpless 1995;Donaldson 1990). In post-war Japan, the same discourse reinforced a deep-seated stereotype that cast rural areas and lower socioeconomic classes as the source of the nation's 'overpopulation' problem, and cities as enlightened spaces where the educated classes voluntarily practiced birth control. It simultaneously sanctioned the diffusionist view inscribed in the state campaign: the idea and practice of birth control would necessarily flow from 'modern' urban centers to peripheral backwaters.
The IPP birth control survey internalized this developmentalist narrative and opted for regional analytic categories. A focus on regions went hand-inhand with the diffusionist perspective, which was even integrated into research questions. For instance, a survey conducted by Shinozaki in the suburbs of Tokyo asked, 'How much is "birth control" diffused as one travels from the center of Tokyo to its neighboring towns and villages?' and compared data collected from three regions: Tokyo, 'cities and towns in the suburb of Tokyo' and 'villages in the suburb of Tokyo' (K oseish o jink o mondai kenky usho 1949, 21). The result of the survey revealed a higher degree of 'indifference' (mukanshin) to birth control among people in the rural district compared to cities, confirming not only assumptions about lower socioeconomic development in rural areas, but also the argument dominating policymaking at that time: state birth control initiatives should target the countryside (K oseish o jink o mondai kenky usho 1949, 14). This approach to data thus enabled researchers to craft their research findings in ways that were comprehensible for the policy agenda.
On the surface, this focus on regional categories appears disconnected to economic rationale. However, in reality, consideration of the national economy was an omnipresent backdrop. For instance, a mid-1950s policy discussion on the rural population was dominated by the issue of how the economy could absorb the expanding labor force to prevent them becoming 'the complete unemployed' (kanzen shitsugy osha) (O'Bryan 2009). Even after the Japanese economy experienced high economic growth in the late 1950s and concern about unemployment had dissipated, economic consideration formed the core of policy discussions on peripheral populations. In the early 1960s, when members of the IRPP-CPM Second Special Committee brought up the issues of 'population quality' as a policy agenda, family planning was linked to issues of 'regional development' (chiiki kaihatsu). A type of social policy was emerging as a response to Japan's post-war reconstruction efforts, which were by that time being criticized as too weighted toward economic development (Sugita 2015; Zaidan h ojin jink o mondai kenky ukai 1962, 39).
Through sorting data by socioeconomic and regional characteristics, the birth control research inscribed the economic rationale underpinning the state objective of reconstructing the nation. 5 In so doing, it simultaneously categorized respondents' sexual lives in terms of their reproductive and productive capacities. The image of the Japanese population that emerged as a result was that of an aggregate of individuals whose ability to produce labor and Japanese offspring would contribute to the reproduction of the national economy and the nation's population. This portrayal of the Japanese population consolidated the official standpoint, and enabled the prioritization of supposedly stable internal subcategories over the haphazard movements of people breaching Japan's newly formed territorial borders. It certainly left little space for any reflection on racial politics, but rather provided an opportunity to reinforce post-war Japan's officially sanctioned identity, based on a narrative of ethnic homogeneity and amnesia about the country's colonial past.

Conclusion
One could conclude this article by claiming Japan's birth control boom confirms the concept of statecraft presented by Michel Foucault, which has shaped a number of important works on the politics of population and modern government (e.g. Thompson 2012;Park 2008;Greenhalgh and Winckler 2005). The official birth control research was intended to clarify the Japanese population's patterns of reproductive behavior and was organized when 'overpopulation' became a political agenda in post-war reconstruction. Furthermore, the research projected the image of an ethnically homogenous, productive Japanese population at a time when the Japanese state was rebranding itself as an ethnically contained post-war nation state, geared toward reconstruction via economic means. Seemingly, post-war Japan's birth control research presents a perfect example of Foucauldian 'bio-politics of the population' (Rabinow 1991).
This article, however, has explored the story from additional vantage points. Firstly, I have detailed how the survey research was uniquely and directly embedded in post-war Japan's search for a new identity; a specific historical juncture as the dismantling of the Japanese Empire fundamentally reconfigured politics, economy and society (Kushner and Muminov 2017). Secondly, my focus on the birth control survey led by Shinozaki, who identified himself as a bureaucrat and a scientist, effectively enabled me to highlight factors that participated in the co-productive relationship between the making of scientific knowledge and statecraft (Greenhalgh 2008). As this article has demonstrated, knowledge produced through this research deftly paralleled state efforts to govern the Japanese via birth control policy, the former facilitating the latter by clarifying priorities in the mode of state population management. Finally, foregrounding the subjectivity of technical bureaucrats establishes that state-led population management did not simply happen because a policy acted as an embodiment of diffused power, but was shaped by the everyday activities of these bureaucrats. Shinozaki diligently engaged with generating new knowledge for the state and liaised with various stakeholders in the policy implementation process, in part motivated by a sense of duty as a government employee, but also because he believed in the idea of progress and had aspirations to expand his scientific field. At the same time, Shinozaki's activities were compromised due to people's lack of motivation to take part in the survey. The birth control survey resulted from the at times unpredictable situations that required technical bureaucrats to constantly maneuver through layers of interests.
In conclusion, policy science and policymaking maintained a co-productive but fundamentally complex relationship. Yet, it was this complex interaction that ultimately reinforced the process of post-war reconstruction, by providing an epistemological framework with which to imagine Japan's population in terms of ethnic homogeneity and economic rationale. The influence of this social imaginary was expansive: the resulting narrative of the Japanese population had a profound impact on how the Japanese state managed its population for many years to come. war period as a direct translation of 'family planning'. For this article, I follow actors' own use of the terms. For the semantics, see (Obayashi 2006). 2. This is not to say that the process to establish and implement birth control policy ran smoothly. On the contrary, immediately after the war, birth control was a thorny issue both within the Japanese and Occupation governments. For more, see e.g. (Takeuchi-Demirci 2018, 118-119;Oakley 1978, 825;Yokota 1948). 3. Due to their association with family, housewives played a pivotal role in the New Life Movement's birth control program. For details, see the work of Andrew Gordon, Takeda Hiroko, Ogino Miho, and Tama Yasuko cited in the main text. 4. Not all technical bureaucrats specializing in population believed their scientific knowledge should influence policies, with many asserting the impartiality of their investigations. Okazaki Ayanori, the IPP Director, specifically stated that IPP was "a research institute dedicated to the research and investigation of population problems, and it is not part of our duty to come up with any policy recommendation for various kinds of population problems, .including the problem of birth control" (Honda 1953, 1). 5. Because of this formulation, gender played a pivotal role as another vector influencing the characterization of research participants in the survey research. The limited scope of this article has not permitted me to elaborate on this aspect, but in relation to the sexualisation of married couples in post-war Japan, see Ogino 2008b, 228-241.