The aim of this essay is to trace some distinctions in the methodology of demography or population theory between Prof. Minami (1896－1985) of Chuo University and Prof. Ichihara (1926－1982) of Kansai University. In the postwar era (1952－1981) of Japan, they both regularly lectured on Population Theory in the faculty of economics. This paper primarily focuses on two different key points between them. The first point concerns the interpretation of Malthus’s Essays. Minami endeavored to grasp its essence as the two principles (the regulating principle and the principle of increase) of population. From this point of view, he emphasized the progressive and retrogressive oscillations of society, and consequently could find an original model of interdisciplinary population theories in Malthus’s Essays. However, Ichihara argued against Minami’s position. He urged that Malthus only disputed matters while presupposing civil society (based upon private property and monogamy). The second point is as follows: Though Minami insisted that population statistics was merely an auxiliary means to the theory of population in relation to Malthus’s Essays, he argued that demography should be based upon population statistics. Ichihara tried to restrict this proposal from the view of political economics, seeking to reason that population patterns (for example, the law of sex ratio in population) established by the Political Arithmeticians would be the most important starting point in building up this science.

The 1930s saw a major shift in discussions on Japanese population and social policy. As a result of the emergence of Okochi theory, the field of population and social policy became divided into labour problems and living conditions. This paper re－examines population and social policy in prewar and wartime through new perspectives. In this paper, I pay special attention to the eugenic－euthenic principle highlighting issues surrounding the quality of population. I also pay attention to sociological approaches to population and social policies which dealt with living conditions in prewar. The proponents of this approach, led by Yasuma Takata, argued that living conditions should be emphasized in social policymaking.

The aim of this paper is to discuss how T.R. Malthus’s population theory was accepted and interpreted in Japan. In particular, it focuses on the ‘Malthus 150th Anniversary Commemorative Lecture’ held at Kyoto Imperial University in 1916. This lecture played an important role in the reception of Malthus’s population theory in Japan. The content of the lecture reflected the latest knowledge and trends in fields such as economics, history, sociology, and demography, and also included discussions on current statistics, population dynamics, and neo－Malthusianism. The lecture went beyond academic discussions and became a platform for delivering scholarly achievements to the wider public. As a result of its success, subsequent regular commemorative lectures and journal publications were organized, providing a forum for discussion that transcended the boundaries of narrow academic circles and fields.

Based on his sociological and economic research, Yasuma Takata developed his own theory of population and proposed the Third Historical View, which attributes the causes of social change to population. Takata also empirically analyzed population changes, particularly with respect to fertility changes. Accordingly, Takata argued that Japan should actively increase its population in the 1920s and 1930s, when overpopulation was a problem. During the wartime, as a policy for population growth, Takata advocated an overall lower standard of living, the sound upbringing of children, and the maintenance of rural villages as a source of such growth. As wartime society caught up with Takata’s claims about population, he became the ideologue of population policy at the time. However, his population studies, which predicted a decline from an early stage, has some relevance even today, when the birthrate is declining.