Is your city Manhattanizing? Probably not within the next few hundred years. (CHARTS)

Posted by on Apr 14, 2015 in Blog | 0 comments


Every successful city grows and evolves over time, but is your city Manhattanizing?

For those unfamiliar with the term, Manhattanization is best described as the fear among some residents of growing cities that if population growth continues unabated, there will be no room left for anything but townhomes, apartments, and pencil-thin skyscrapers. The streets will be overrun with traffic and tourists, Wall Street will move in, balls will drop on live television, chaos will ensue.

For those of us who have been to (and enjoyed) New York, this may not sound so terrifying. But for many people, it seems to be a real concern: A cursory Google search reveals writing on the subject all across North America, from Los Angeles, San Francisco, Seattle, and Las Vegas, all the way over to Boston and Toronto. Curbed Miami has its own “Manhattanization of Miami” search tag. Even Brooklyn, right across the East River, has its doomsayers.

The question is, what would Manhattanization actually look like for these and other large U.S. cities? How much would they need to grow to reach Manhattan’s current population density of approximately 70,000 people per square mile? And, at current growth rates, how long would it take them to get there?

The answers can be found below in two graphs, compiled from U.S. Census and American Community Survey data. The first compares the current population of many cities (note: cities, not metros) to what their populations would be at 70,000 people per square mile—not surprisingly, most cities would be much, much larger. Even the closest to complete Manhattanization, New York itself, would need to almost triple in population. San Francisco, the next closest, would have to more than quadruple its population. In the graph, the black line for each city represents its current population, the blue bar is population at 70,000 people per square mile, and the number to the right of each bar is the population multiplier—how many times larger the city population would be if it grew to the density of Manhattan.

What this graph illustrates pretty clearly is that every city in the U.S. has a long way to go before even approaching true Manhattanization. While select neighborhoods may be quite close—my neighborhood in Koreatown, Los Angeles houses about 40,000 people per square mile, for example—citywide or even large-scale Manhattanization is far out of reach for most cities, even relatively dense places like Boston and Chicago. And while many of us wouldn’t find it appealing to have such densities spread uniformly throughout our cities, most of us can appreciate the value that a variety and diversity of urban typologies brings to our lives. These numbers demonstrate that regardless of where you live, your city has plenty of room for a wide range of neighborhoods, from single-family to skyscrapers and everything in between.

The next graph looks at how quickly cities grew between 2000 and 2010, and uses that information to determine how long it would take to grow to the population density of Manhattan, assuming that the same growth rate continues forever. For the small number of cities that actually lost population over this time period, we looked at growth between the 2010 Census and 2013 one-year American Community Survey. Annual growth rates are compounded in this analysis, so 2% annual growth would more than double the population of a city over a 50-year period.

Based on current growth rates, the cities with the highest population density today would not be the first ones to reach 70,000 people per square mile. This is mainly because larger, denser cities tend to grow more slowly. In reality, places like Raleigh and Bakersfield won’t be achieving Manhattan-esque (or even very high) population densities any sooner than New York or Boston, because as they continue to grow in population their annual growth rates will decline. Select neighborhoods in larger cities grow rapidly—such as Downtown LA, which accounts for 1 percent of Los Angeles’ land area but 20 percent of its growth—but the overall decades-long trend has been for construction and population growth to slow down as new regulations are put in place and urban construction costs increase.

Another caveat is that the above graph doesn’t take into account the physical expansion of cities: While places like San Francisco and Manhattan are physically constrained by geographic features (i.e., they can’t grow into the water), other cities are not so limited. Raleigh, Bakersfield, and Charlotte all increased their populations by at least 35 percent between 2000 and 2010, but they also increased their physical footprint by at least 25 percent, so their density changed relatively little.

One last map, below, compares population growth to the physical expansion (through annexation, generally) of various U.S. cities. It shows that while many cities grew significantly in population between 2000 and 2010—represented by larger bubbles—some grew by increasing density, while others grew primarily by increasing their land area—darker green means that population growth exceeded physical expansion, red means that expansion was greater than population growth. Examples of all different types appear in the map. Austin shows up as large and red because it added many residents, but it increased its physical size to an even greater degree. Detroit and Cleveland are small and red because they lost population and did not increase their footprint; Memphis is relatively small and red because, while it grew slightly (1.0%), it increased its footprint by much more (13.6%).

Many cities, including Phoenix and Chicago, are grey because their population growth and physical size grew in rough proportion to one another, so that densities were mostly unchanged. These provide some context for the above map, highlighting why looking at just population growth can be misleading. Last, there are cities that increased their population significantly more than they physically expanded, and these show up as darker green.

Overall, current growth rates for most large cities seem to indicate that the threat of Manhattanization is overblown. Despite claims of record growth and a booming development sector in many cities, new unit construction remains far below peak levels for many cities. Rather, growth has been relegated to such a small number of density-friendly communities that it has become far more visible, even as its absolute numbers have declined.

The term “Manhattanization” is also sometimes used to the extreme gentrification characteristic of the borough—the kind that displaces lower-income and middle class residents and gives it the perception of being a playground for the rich, not a place where average, everyday people live. Paradoxically, however, it’s the fear of increased density that led to coastal cities becoming the most expensive housing markets in the country. In response to the anti-growth, anti-“Manhattanization” movement, places like Los Angeles have successfully reduced their population capacity through a combination of new regulations, legislation, and bureaucratic processes that put a hard cap on growth. Those caps haven’t stopped cities from attracting more businesses and residents, but they have ensured that every new resident has to outbid a current resident for the privilege of living here—a recipe for guaranteed gentrification and displacement.

Knowing what we know now—that putting a halt to construction places the burden of growth on our poorest residents, and that every city has plenty of room for additional housing without having to fear Manhattan-style crowding—our focus now should be increasing the supply of housing at all income levels. We should encourage every type of housing: luxury because it will produce revenues necessary to subsidize affordable housing construction, and because it takes the demand pressure off homes in the middle range; moderate-income housing because our cities won’t succeed without teachers, office workers, or students; and low-income housing, because no matter how much we build, market rates will always be out of reach for some, including many of our seniors. If we finally commit to this course, and after a few hundred years of providing our residents with a better, more affordable quality of life, it turns out that we’ve built ourselves another Manhattan or two, well, that doesn’t sound like such a bad trade.

Note: For those interested in larger versions of these charts and map, they can be found at the following links. Feel free to share with attribution to Urban One.