A new list ranks the wealthiest cities in the world by the number of the wealthiest residents. Do the wealthy in suburbs count? For New York City, the top city on the list, they appear not to:

The Big Apple is home to 345,600 millionaires, including 737 centi-millionaires (with wealth of USD 100 million or more) and 59 dollar billionaires. New York is the financial center of the USA and the wealthiest city in the world by several measures. It is also home to the world’s two largest stock exchanges by market cap (the Dow Jones and NASDAQ). Perhaps most notably, total private wealth held by the city’s residents exceeds USD 3 trillion — higher than the total private wealth held in most major G20 countries…
It should be noted that there are several affluent commuter towns located just outside New York City that also contain a large amount of top-tier wealth. Notables include: Greenwich, Great Neck, Sands Point and Old Westbury. If these towns were included in our New York City figures, then billionaire numbers in the combined city would exceed 120.
The San Francisco listing, #3, includes a broader set of communities:
The San Francisco Bay area — encompassing the city of San Francisco and Silicon Valley — is home to 276,400 millionaires, including 623 centi-millionaires and 62 billionaires. Home to a large number of tech billionaires, Silicon Valley includes affluent towns such as Atherton and Los Altos Hills. This area has been steadily moving up the list of millionaire hubs over the past decade and we expect it to reach the top spot by 2040.
Los Angeles, #6, also includes suburbs:
This area is home to 192,400 resident millionaires, with 393 centi-millionaires and 34 billionaires. Our figures for this area include wealth held in the city of Los Angeles, as well as nearby Malibu, Beverly Hills, Laguna Beach, Newport Beach, and Santa Monica. Key industries include entertainment, IT, retail, and transport.
And the methodology suggests there are six cities on the list where the city is defined more broadly.
There could be a variety of reasons for looking at wealthy residents just in cities or also including metropolitan regions. Depending on setting these different boundaries, how much might it change the rankings?