Demographic explosion in Meiji Japan

During the Meiji period, the population of Japan increased from 33 million to 53 million 362 thousand people. The reasons for this rapid growth remain unclear. Usually, scholars mention the development of medicine and the improvement of the hygienic skills of the population, economic development, an increase in the standard of living, the reduction of infanticide. However, these explanations appear to be insufficient. In this article, I am trying to understand in more detail what exactly caused the population explosion of the Meiji period. I conclude that the main factor contributing to the increase of the population was the growth of the marriage rate, which was not paid due attention to before. The demographic theory believes that there is an intermediate stage between the traditional type of reproduction (high fertility and high mortality) and the modern (low fertility and low mortality). It is characterized by a decrease in mortality, while the birth rate remains high for some time. This leads to an increase of population and accelerates population growth. However, the Japanese historical experience shows that this theory, developed primarily on European sources, turns out to be applicable to Japan only with significant reservations: significant population growth begins in the second half of the Meiji period in conditions when the mortality rate has not yet dropped. It begins to decline only in the second half of the 1920s. That means that the increase in the birth rate preceded the decrease in mortality. Only after that do we observe a synchronous decrease in both mortality and fertility. Thus, for half a century, Japanese realities "ignored" Western theory.