*This article is based on the latest information and speculation as of December 2025.

1. Definition of Consensus Building and Paradigm Shift: From DAD to EDD

Shift from "persuasion" to "convincing"

Let's start with a definition of the term. "Consensus building in urban development" refers to a series of dynamic processes in which parties with different positions, such as government, residents, landowners, private businesses, and experts, deepen mutual understanding through information sharing and dialogue, and find "satisfactory solutions" regarding the validity of plans and their future vision.

It is important to note here that consensus building is not synonymous with "everyone agreeing with something with their hands raised." Complete unanimity is merely an illusion in today's complex society. Rather, the essence of consensus building is to make conflicts and disagreements of interest visible and ensure "procedural justice" in the process of reconciling them.

In the past, urban planning was dominated by the "DAD model" (Decide-Announce-Defend), in which experts and the government would formulate a plan, announce it to the public, and defend it against any opposing views. While this was efficient, it had structural flaws that made it easy for citizens to distrust the plan.

What is needed today is a paradigm shift to an "EDD (Engage-Deliberate-Decide)" model, in which citizens are involved from the early stages of planning, deliberate together, and then make decisions. This is not just a change in methodology, but a qualitative transformation in democracy.

2. History and Institutions: From Developmental Dictatorship to Assessment

What the anti-pollution movement brought about

Unraveling the history of consensus building in Japan is also about tracing the history of the maturation of civil society.

During the period of rapid economic growth from the 1960s to the 1970s, Japan pushed ahead with the construction of large-scale infrastructure such as dams, highways, and industrial complexes under the "Archipelago Remodeling Theory." However, this came at the cost of serious pollution and destruction of the environment, sparking fierce opposition movements in various places known as "NIMBY" (Not In My Back Yard).

This was the moment when the resignation of "we can't go against what the government has decided" was transformed into a sense of right to "we must protect our living environment." Against the backdrop of this social pressure, "environmental assessments" were introduced as a system for scientifically and objectively evaluating the merits of development.

Cultural differences seen in a comparison between Japan and the United States

The origins of the environmental assessment system lie in the National Environmental Policy Act (NEPA), which was enacted in the United States in 1969. However, in the process of its introduction into Japan, its operation has evolved in a unique way.

The table below compares the characteristics of assessment and consensus-building processes in Japan and the United States, highlighting the differences in legal culture.

In other words, while the United States has a strict system based on "conflict and judicial decisions," Japan has a flexible system based on "cooperation and administrative guidance." Systems like Japan's "Pollution Prevention Agreement," which function as a gentleman's agreement between the parties even though their legal basis is vague, are unique even from a global perspective.

However, this Japanese-style coordination based on "unspoken understanding" is becoming less and less effective in today's world, where population mobility is rapid and values are diversifying. What is needed is a new skill set that allows for consensus building through "words" and "data" rather than "reading the air."

3. Comparing Methods: Participatory Ladders and Digital Democracy

Arnton Arnstein's "Ladder of Participation"

So, what specific methods can be used to achieve high-quality consensus building? Here, we should refer to the "Ladder of Citizen Participation" theory proposed by sociologist Arnton Arnstein in 1969.

She classified the levels of citizen participation into the following eight stages. Let's compare them with the current situation in Japan.

Unfortunately, the reality is that the "public comments" and "explanatory meetings" in many administrative procedures are merely tokenism, at the third or fourth step of this ladder (information provision and consultation). We must always ask ourselves whether they are merely a way to "vent frustration" or to create an alibi as a "ritual."

DX opens up new horizons

However, there is no need for pessimism. The wave of digital transformation (DX) is also bringing about changes in the way consensus is formed.

For example, Decidim, a participatory platform originating in Barcelona, Spain, is being introduced in Japan in cities such as Kakogawa. In traditional face-to-face workshops, the opinions of older people with more time on their hands and loud activists tend to be over-represented. However, by utilizing online platforms, it is becoming possible to gather the voices of the "silent majority," such as those raising children and young people.

Even more noteworthy is the use of generative AI. In cutting-edge examples such as Tsukuba City, AI is used to analyze the vast amount of opinions submitted by citizens, conducting sentiment analysis and structuring the key points of discussion. This makes it possible to visualize complex conflicts of interest that humans cannot process, and is beginning to make "hybrid consensus building" a reality, leading to more creative solutions.

4. Case study analysis: The challenges of "Shukuju" in Toyako Town

To put theory into practice, let's take a closer look at the case of Toyako Town in Hokkaido. The challenges facing this area are emblematic of the difficulties facing regional cities in Japan in achieving "Shrinking Smart."

The trilemma of tourism, conservation, and population decline

Toyako Town is a world-famous scenic spot certified as a UNESCO Global Geopark, and is visited by many tourists throughout the year. However, the town is in a state of three-way conflict between tourism promotion, environmental conservation, and measures to combat population decline.

1. Asymmetry in budget allocation
An analysis of the fiscal year 2022 budget reveals an interesting deduction. A huge budget of approximately 64 million yen has been allocated to the "Lake Toya Long-Run Fireworks," a major tourist attraction. This is an investment in "short-term returns," which is likely to have a direct economic effect and is therefore most likely to gain the consent of businesses and townspeople.
On the other hand, the budget for "geoparks," which protect the core of these tourism resources, is extremely small. This huge difference in budget reveals the dynamics of consensus-building, where immediate profits tend to take priority over future risks (loss of tourism resources due to environmental degradation).
　表面的に見えている数値による比較に過ぎませんし、良し悪しを推しはかることができるものではありませんが、非常に興味深いデータです。

2. The looming "demographic cliff"
Even more serious is the population problem. The town's population vision aims to maintain a population of 6,800 by 2040 and 5,500 by 2060. This is not a case of maintaining the status quo, but a grim prediction that the population will shrink to this level even if strong measures are taken.

As the population declines, the cost of maintaining infrastructure per person will skyrocket. In the future, we will inevitably have to face painful discussions about the consolidation and elimination of public facilities and the consolidation of residential areas. The traditional approach of building a consensus based on profit-driven initiatives (by creating something for everyone) will no longer be viable. Dialogue based on a high level of ethics and consensus on how to share the disadvantages fairly will be essential.

5. Conclusion: Process as an investment in the future