is right behind, or above, urban population growth.

“Everything we’ve heard about global urbanization turns out to be wrong”, say some EC researchers (*). They argue that widely accepted numbers on how much of the world’s population lives in cities are incorrect. One very common reason would be that every country defines what is a city in a different way. Another is differences in data collection schedules and policies: one country may run a census every decade, another every two.

Another reason is, unsurprisingly, money: let’s assume, for example, that some country defines a city as “any conglomerate with at least fifty thousands residents”. Now, if a party wins the elections promising, among other things, that it will connect every “city” by high speed railways, it will also have an interest, if money is tight, to not publish, or delay, new census data showing that there are, say, ten more cities to connect than everybody assumed (especially if some of those cities are governed by other parties).

At the internation level, this has big consequences, because:

• “If you leave it to every country to define its own administrative boundary of what is urban and what is rural, then you have no benchmark for comparability”

whereas “a consistent definition would benefit policymakers at the global level as they seek to respond to new international agreements calling on countries to encourage sustainable cities”.

So the problem, again, is money, and spending it in the most effective way, and the same article explains why: “a lot of development aid [still] geared toward rural." In other words, if the majority of [the poorest!] people already lives in cities, but the United Nations, World Bank, European Union and the likes are still told that most poor people still live in rural settings, a lot of development money will be spent in the wrong place, period.

The slums of big cities already cities suck. If more people than we thought already live there, it becomes even more urgent to fix them. For the same reason, it is even more important that our Caves of Steel are really Open.

Of course, things are not so simple. To begin with, should the world agree on one, single definition of “city”? Shouldn’t every single country, if not culture, be entitled to its own definition of what is urban and what is rural?

The only thing that is certain is that Open Data on cities worldwide, or at the very least: Open Data on how data about cities are generated in each country are badly needed.

Final practical suggestion:

Do you know the exact, official definition of a city in your country? If not, find it out, in your own interest. And once you have it, please do let me know!, thanks!

(*) For more background on the same general topic, you may also want to have a look at the results of the “geographical dimension and the new urban agenda” session, which discussed “data need at the local level” in order to “leave no one behind”.