Tokyo is Asia’s first megacity: its urban agglomeration topped the symbolic ten million inhabitants marker sometime after World War II. While it had been one of the world’s largest cities for centuries, arguably its most relevant growth spurt took place between 1950 and 1970. It was during this period that the already enormous urban agglomeration doubled in population. I call this phase of the city history the “Tokyo moment” (i.e., twenty years of rapid population growth to an already large urban area).

Using these criteria (the doubling of the population within two decades, thereby exceeding 10 million inhabitants within the twenty-year time span), the following agglomerations have had (or are having) one or multiple “Tokyo moments,” according to data from the United Nations (UN):

There are 34 megacities today by the UN’s count. Many more cities have doubled in size within the time frame of twenty years. However, the “Tokyo Moment” club is more exclusive, consisting of only 19 cities as shown in the table. These can be regarded as the founding members of a new megacity discourse, or put more simply, that of rapidly-growing, big cities.

These 19 cities only represent 7.9% of the world’s urban population in 2020, and yet they claim an outsized share in the debate on the urban twenty first century. This urban century is also an Asian century as the continent is reclaiming its pre-modern share of the world economy. It is unsurprising, therefore, that Asian cities take 13 spots in this list (or 68.4%), somewhat more than the continent’s share in the global population in 2020 (59.5%).

As Asia’s first megacity and the world’s largest urban agglomeration until today, just how instructive is Tokyo’s 1950-70 experience for other developing cities, primarily those in the various subregions of Asia? I have been asking myself whether the city was a trailblazer and model or an outlier and special case with limited relevance today.

As my research is situated at the intersection of economic history and development studies, I have structured my work along two main threads: first, the city as a site of production and second, the city as shelter. I find that Tokyo’s experience indeed holds important lessons for other big and fast-growing cities. However, we have to understand the idiosyncratic influence of Tokyo’s institutions and planning decisions on these two threads. Combined, Tokyo’s experience can help lay the foundations for an emerging field of the “history of megacities.”