Comparing sizes of populated areas is challenging because of a wide variety of definitions for city limits and metropolitan boundaries. The United States Office of Management and Budget (OMB) defines its metropolitan statistical areas (MSA) and micropolitan statistical areas (μSA) at the county level (or county equivalent: boroughs in AK and parishes in LA), while Mexico’s National Institute of Statistics and Geography and Statistics Canada define their metropolitan areas at the municipality level. Other nations may only define metropolita areas for their largest areas.

For this reason, populations of MSAs and μSAs in the United States tend to be larger than comparable Canadian Census Metropolitan Areas (CMA) and Census Agglomerations (CA). Furthermore, Mexico defines its Zonas Metropolitana (ZM) very strictly, more like United States’ urban areas (UA) rather than MSAs. Mexico has nothing comparable to μSAs of the United States or CAs of Canada, and neither nation has anything officially comparable to Combined Statistical Areas (CSA) of the United States, which are connected groups of MSAs and μSAs.

So, I became curious what the populations of all North American areas would be if they were defined similarly to the OMB metropolitian areas.

Canada has census divisions, the closest Canadian equivalent of Unites States counties, so these were used to create Canadian OMB-style MSAs and μSAs. Unfortunately, Mexico has no administrative or census division between the state level and the municipality level. However, Puerto Rico has the same structure, and here the OMB generously awarded these small municipalities (municipios) to the CSAs and MSAs of Puerto Rico. The San Juan-Carolina CSA, for example, is composed of 48 of these municipios. Making Mexican areas comparable to United States MSAs and CSAs required examining patterns of population density and infrastructure to enlarge the ZMs to areas comparable with Puerto Rican MSAs, and also to combine these into areas comparable with Puerto Rican and United States CSAs.

The other nations of North America have top-level subdivisions with comparable sizes to some of the larger U.S. States, and therefore, these top-level divisions were used to define comparable areas for these nations.

Additionally, the OMB defines metropolitan divisions within its largest metropolitan statistical areas, so I also pondered what these areas might look like when defined in a similar way.

• Populations for counties, municipios, and census divisions for 2020 were taken from citypopulation.de.
• Definitions for the United States statistical areas were taken from the delineation files at census.gov.
• Definitions for all other CSA-, MSA-, and μSA-like areas are based on educated guesses by me using Canadian census divisions, Mexican municipios, or top-level administrative divisions in other nations.

For example, the population of the Toronto CMA is comparable in size to the Philadelphia MSA. The Philadelphia CSA includes the surrounding MSAs of Reading, Atlantic City, Dover, Vineland, and Ocean City, but not the areas of Allentown or Lancaster.

As a comparison, it would seem appropriate for a Toronto CSA-like area to include Oshawa, Hamilton, Barrie, Brantford, and Orangeville, but not the areas of Kitchener or Peterborough.

This would make Toronto the seventh largest primary stastical area in the United States or Canada, instead of twelfth, which would be its rank using Toronto’s CMA population against the primary statistical areas of the United States.

As another example, the municipality structure of Mexico is similar to that of Puerto Rico, where the CSA of San Juan includes the MSAs of Arecibo and Guayama, whose centers are about an 80 and 90 kilometer drive, respectively, from the center of San Juan.

By comparison, the population center of Monterrey is a similar distance to Saltillo, and the population center of Guadalajara is a similar distance to Ocotlán. Comparisons for Mexico City, the largest metropolitan center in North America, were made with New York City, which runs a close second, and where the population centers of Trenton and New Haven are roughly 110 and 120 kilometers away.

Finally, I added a table for statistical areas crossing international boundaries, such as Buffalo-St. Catherines or San Diego-Tijuana.

Nothing about this is official; I was simply curious to imagine these comparisons.