Tokyo

People considering relocation or buying a home look first at the income figures. Prefectural income per capita ranks 1st in Japan, and it greatly exceeds even the line you would expect from the metropolis’s overall strength—an upside swing beyond its underlying base. But turn one more page of the same data, and the home-ownership rate is low and the birth rate is dead last. That the total volume of affluence breaks through the ceiling, and that this affluence reaches your own household and daily life, become separate stories in Tokyo—this is the front and back of concentration.

The back side is split more finely still. While income stands out, the lowness of the unemployment rate also stands out, and the average smooths over and conceals this unevenness. Even the unemployment rate and the home-ownership rate, which tend to move together in many prefectures, point in opposite directions in Tokyo alone. The wealth it gathered flows to employment, yet it does not flow all the way to housing stability. As long as you look at an overall ranking or a single deviation score, this lopsidedness of concentration never comes into view.

In other words, Tokyo’s evaluation is close to a single-point standout type supported by one thick pillar. Pull that pillar—concentration—out of your head once. What remains? To ask not the total volume of affluence but the range that affluence reaches. That is the only correct doorway into reading this metropolis. The moment you cover over income’s 1st place and the birth rate’s 47th place with the single phrase “so very Tokyo,” the front and back of the verb “to gather” come to look equally thin.

From here on too, what moves Tokyo is the same concentration. Concentration first swings it upward. Its symbol is the Linear Chuo Shinkansen—but here caution is needed. In March 2024, JR Central formally abandoned its target of opening the Shinagawa-Nagoya section in 2027. Work could not begin in the Shizuoka construction zone over the water-resource problem of the Oi River, and more than eighteen construction zones overran their original schedules. The opening has slipped into the 2030s, and this can only be read not as a “settled future” but as a “plan whose timing keeps moving.” The Haneda Airport Access Line and the redevelopment of Shinagawa, Yaesu, Shinjuku, and Shibuya still work in tandem at that very Shinagawa to thicken the concentration further.

But the upside swing has a lifespan. The IPSS projection sees the net inflow of the young to the 23 wards continuing for the time being, but slowing from 2040 onward. Overseas investment into the city center, set against a weak yen and the recovery of inbound visitors, is also a short-term force that sways with exchange rates and regulation. The force that swings upward through gathering will work over the coming decade, but it will not last forever.

And concentration swings downward, too. A Tokyo-area inland earthquake (M7 class, southern Kanto), which the government’s Earthquake Research Committee evaluates at “about 70% within the next 30 years.” The timing is uncertain, but the certainty is an official government figure and the scale of impact is extreme—the more a city has gathered people and assets into a single point, the more it stands to lose in a single blow. The generational turnover concentrated in 2031–33 and the rising vacant-home ratio crumble the very “premise of expansion” seen in the past section.

Which to weigh more heavily on your own time horizon—the material for that is opened in the development roadmap below, as schedules, plans, and certainties. The same verb, “to gather,” produces both the upside and the downside—I want to observe this not rounded into a single scenario but as the swing range itself. Wealth, employment, and the threat of a Tokyo-area inland earthquake are all products of the same concentration.