Urbanization index, updated

I’m working on a comprehensive listing of all of the world’s countries, provinces, districts, with data down to the district level. One of the things I want to do is include an urbanization index.

I’ve written about this before here. In that initial stab, the index was based on three factors: the population of the district, the percentage of the population that was considered “urban,” and the number of urbanites.

The problem, as I began working through this, is that the index doesn’t scale at the district level. At the province and country level you can find urbanization statistics – and indeed, that’s exactly what the World Christian Encyclopedia did. For every country of the world, Todd Johnson (who did that piece of intellectual work, and did it brilliantly in my estimation) provided % urban, % rural, and then a list of the major cities (I think above 10,000 in population, or maybe it was just those above 100,000 in population). The % urban generated total urbanites, and the population of those in the major cities could be subtracted from total urbanites to get the number of urbanites living in minor cities. Worked great.

But figuring out % urban at the district level is another matter altogether. Often the countries don’t provide % urban even at the province level.

Urbanization is important because outreach to urban areas is quantifiably and strategically different than outreach in rural areas. Urban areas can be gateways to rural areas, and are often easier to live in and easier to reach – but if you only have ministry targeting urban areas, you’ll leave out half the world. So I want to be able to figure out some sense of urbanization.

Fortunately, the key to this in my opinion is to go back to the definition of urbanization. Urbanization by most authorities is simply a built up space with high population density. When you get a lot of people living in close quarters, they tend to build structures that enable them to continue doing so – to live together, manage power and waste and water, interact in markets, govern, control crime, etc.

Whatever works to indicate urbanization has to be scalable so that I can do large masses of provinces and districts almost at a glance. You can’t go through 3,000 rows and spend a lot of time intellectually wondering. So, some ways to do this:

• Population density, which is simply a function of total area and total population. I have square kilometers for every province, and a population estimate (at least an indexed population estimate) is a goal for the document. So, from this you can derive a rough population estimate.
• Definition of the district as a metropolitan area. Many districts that contain larger cities are defined as the city itself (e.g. Phnom Penh, Cambodia, is the capital city, and is defined as a province. The whole province is considered urban.)
• The ability to look on Google Maps and tell at a glance whether a province or district is urban or not.

So here’s my new index, based on global measures of population density for urban areas:

-2, density of 0 to 25/km2 -1, density of 25 to 50/km2 0, density of 50 to 100/km2 +1, density of over 100/km2 +2, density of over 200/km2 (Australia, USA measure of an urban area) +3, density of over 400/km2 (Canada, India’s measure) +4, density of over 1,000/km2 (China’s) +5, Part of a larger metropolitan area (e.g. Cairo is part of Greater Cairo) +6, Very large global city (like New York or Istanbul)

If I don’t have the population densities, a quick system I’m using until I can more precisely estimate it:

R, over three quarters rural, no visible townships on a Google Map r, largely rural, but visible townships or cities on a Google Map ., about half and half, numerous visible cities but large open spaces as well c, A quarter to a half of the district is taken up by a few larger cities C, Three quarters to the whole district is a large city (or two)

Thinking about this strategically, consider the areas in which you work. Are any lower-urban or rural? Any higher-urban or rural? How do the higher urban areas relate to the more rural areas? Are there migrants into the urban areas? Do they have family connections back home? How does the Gospel travel over these areas? Is a lot of of work focused on the urban areas, at the expense of the rural? Are there noticeable gaps in outreach because rural areas are difficult to get to?