In July 2025, 200 municipal chiefs flew to Bogotá. They represented 50 cities from 33 countries — the finalists in the sixth Bloomberg Philanthropies Mayors Challenge, a global competition to find and fund the boldest ideas in city government. For three days at the Ideas Camp, they worked with experts, debated their proposals, and tested their concepts against each other and against the harder question: will this actually work?

In February 2026, 24 cities were announced as winners. Each received $1 million and operational support to bring their idea to life.

The Mayors Challenge began in 2014 with a simple hypothesis: city governments, given resources and encouragement, would produce more innovation than anyone expected. More than a decade and six rounds later, the hypothesis has been confirmed. The Challenge has now reached 337 cities globally, influencing programmes that touch over 100 million residents. The winning ideas range from AI-powered school bus routing in one city to digital permitting that eliminates corruption in another, from early literacy programmes that have spread internationally to AI databases that let citizens track and respond to planned urban development.

The 2025-2026 Challenge was the most competitive yet. More than 630 cities applied. The finalists came from Boise to Belfast, Ansan to Addis Ababa, Toronto to Taipei. The advisory committee included Norman Foster — who in the same month was at the Bloomberg CityLab Madrid forum confirming what he has always believed: the best urban interventions are not the most technologically complex but the most precisely targeted at the problems that make ordinary city life worse.

The challenge was launched by Mike Bloomberg at Bloomberg CityLab in Mexico City in October 2024. The Ideas Camp was in Bogotá. The final decisions were made by a committee that included a former US Secretary of Transportation, a retired admiral, the founder of the African Futures Institute, and the Secretary General of United Cities and Local Governments.

What the 24 winning cities have in common is not their size, their wealth, or their geography. It is the quality of the question they asked. Every winning proposal begins the same way: here is a problem in our city that the market will not solve and the national government has not solved. Here is what we are going to do about it.

"The most effective governments today are not just adding programs," said Admiral Michael Mullen, a member of the advisory committee. "They are rebuilding the machinery of government itself."

That sentence, delivered at the announcement of the winners in February 2026, is the most important thing said about city government this year.

(Sources: Bloomberg Philanthropies / Bloomberg Cities / Inside Philanthropy — February–March 2026)

New York 🇺🇸 — Bloomberg Philanthropies is headquartered in New York. Mike Bloomberg built his mayoral legacy — three terms, 2002 to 2013 — on exactly the proposition the Mayors Challenge institutionalized: that cities, not national governments, are the first line of response to the problems that affect most people's daily lives. Zohran Mamdani, New York's current mayor, operates from a completely different political philosophy than Bloomberg did — but the structural argument is the same. Cities are where governance either works or doesn't. New York's current experiment — free broadband in public housing as a civic right, childcare as a budget line, water infrastructure as the question behind every affordability conversation — is the most visible test in the world of whether a large city government can be rebuilt from the inside rather than reformed from the outside. Mamdani was not a Mayors Challenge finalist. But his administration is asking the same question every finalist asked: what would change if we actually fixed this?

Tokyo 🇯🇵 — As of January 1, 2026, Governor Yuriko Koike of Tokyo became the Chair of the OECD Champion Mayors for Inclusive Growth Initiative — the first Asian leader to hold the position, leading a coalition of more than 100 mayors worldwide. Her appointment is the institutional recognition of what Tokyo has been doing under her leadership since 2017: expanding childcare access, promoting female entrepreneurship, advancing workplace equality, issuing the world's first internationally certified resilience bond, and positioning Tokyo as a global leader in climate preparedness. Koike's summary of why mayors matter is precise: "Cities feel climate, demographic, and resource pressures most acutely." Not national governments. Not international institutions. Cities. The Bloomberg Mayors Challenge and the OECD Champion Mayors initiative are two expressions of the same conviction.

London 🇬🇧 — London's relationship with the Bloomberg Mayors Challenge is layered. Norman Foster, who served on the 2025-2026 advisory committee, is based between London and Madrid. His presence on the committee is not ceremonial — it reflects his lifelong conviction that architecture and urban governance are expressions of the same underlying question: what do we owe each other as people who share a city? London itself has not been a Bloomberg Mayors Challenge finalist — the Challenge is designed for cities that face specific, addressable problems and have the political will to attempt solutions. London's problems are large and specific: housing costs, Thames Water's infrastructure crisis, the gap between world's-best-city rankings and the lived experience of its working population. The machinery of London's government is not broken. It is, arguably, not bold enough.