Sunday, July 15th, 2007
In another in my series of articles comparing the twin cities of Indianapolis and Columbus, I’ll present some market size data. It is incredibly difficult to give a true apples to apples comparison of the sizes of cities. City limits are highly arbitrary. Big parts of metro areas are often rural. There are many different ways one can compare two cities, all of them have various strengths and weaknesses. Some of these are:
- City population – This is the actual population of the city itself. I usually consider this the worst measure since city limits vary so much in size. Though you can tell certain things about a market by the size of its central city. For example, I believe one reason Chicago thrived and St. Louis declined is that Chicago is a huge central city with over 2.7 million people whereas St. Louis had a much smaller central city in terms of population and geography.
- Central County population. I actually like this measure for certain things like comparing crime rates. It can be a sort of proxy for city population in some regards.
- Urbanized Area. This is a little known measure that is seldom referred to but I believe is the best way to compare apples to apples across cities. This is just what it says, namely the area that is contiguous and urbanized around an urban core without regard (mostly) to jurisdictional limits. The only downside is that it is difficult to get non-population data sliced this way.
- Metro Area (MSA or CSA). This is widely used and is much better at giving a sense of how big a “city” really is. Lots of data is available sliced this way because MSA’s are always defined out of entire counties. However, they can mislead because of that, particularly in western states with gigantic counties. The Los Angeles CSA area extends all the way to Nevada, for example, and includes huge amounts of desert.
- BEA Economic Area. This is another little known measure. The Bureau of Economic Analysis divides the country into trading areas that represent sort of the the separate “economies” around major cities. These are much larger than MSA’s, but again I think can be useful.
- TV Market Size. This is defined by a private company – Nielsen Media Research – but is very important in corporate decision making. Nielsen calls its markets DMA’s, or dominant market areas, and talks about households rather than people.
So how do Columbus and Indianapolis compare? Here area some measures:
|City Population (2006)||733,203 (#15 nataionlly)||785,597 (#13 nationally)|
|Central County (2006)||1,095,692 (543 sq mi)||865,504 (403 sq mi)|
|Urbanized Area (2000)||1,133,193||1,218,919|
|BEA Economic Area (2005)||2,563,031||3,271,617|
|Nielsen DMA (Households)||898,030 (#32)||1,060,550 (#25)|
As you can see, which city is “bigger” depends on which measure you look at. But I believe these statistics reinforce that for all practical purposes, they are the same size.