What’s the largest city in the world? This seemingly simple question is actually rather complicated to answer. In my post Concentric Londons, I noted how you can define the city in various ways (and I still missed a few), while my complaints about the interesting but flawed visualisation showing “how much room would you need for the world’s population if the city were as dense as…” noted that the cities picked were defined very differently.
It turns out that the BBC’s excellent More or Less tackled the issue in a special edition, which (thankfully) is also available as a BBC News Magazine article (for those of us who prefer reading words to hearing them). After noting some of the problems I’ve covered - is a city the same as the government region defining it, or is it a contiguous urban area, or perhaps a zone of influence? - they settle on Tokyo/Yokohama, at 30 million plus, as the most reasonable answer to the question.
Curiously, it turns out that there is no official UN (or other reliable worldwide) definition of a city. Where Paris excludes its periphery, London extends nearly to the M25; where New York excludes Jersey City, Greater London expanded in the 1960s to swallow chunks of Essex. That’s not even to consider cities such as Cairo, Nairobi, or Rio de Janeiro, where informal building means a density and sprawl that’s a laissez-faire economist’s dream.
However, that wasn’t the end of the show. The final section covered China’s cities, which, if you believe the numbers, are growing like nothing on earth. However, the numbers may not be that trustworthy. Official statistics, as noted by guest Professor Kam Wing Chan, conflate cities with provinces, which can be largely rural, inflating estimates by as much as a factor of five:
The largest city in China is actually Shanghai. It is commonly thought to have a population of 20 million, but Professor Chan thinks 16 million is a better estimate.
He says everyone just loves to think China’s cities are bigger than they actually are. He has even had to correct fellow experts at a world conference on global megacities of the future.
One thing’s for certain: you can’t take the numbers at face value.
So, apparently this picture got picked up by the world we live in and is now doing the rounds. Great!
Only trouble is that Tumblr makes it really hard to know this stuff is being shared. It’s only because I saw an unusual amount of activity that I went into my Flickr stats and discovered that it had more than 500 notes from other Tumblrs! Surely there’s a better way for me to know what’s happening to my stuff? Can’t somebody join the dots?
Hm. Once you know something is on Tumblr, tracking it is easy: likes and reblogs tend to show up in templates, and if they don’t, there’s the API (or the Dashboard) to see. From that point of view it’s better than Twitter, where you get no visibility on favourites, although it’s probably only on a par with Flickr, which has the aforementioned stats for pro users, and Recent Activity (including showing who faved things) for everyone.
For the larger point, though, I suppose there might be a programmatic way of doing that. Google’s profile (based, I believe, on link rel=me data) knows that I have husk.org, flickr.com/photos/blech and notes.husk.org, and so Tumblr could (if they were so inclined) notify me on my dashboard if something from any of them were linked to.
I can imagine it taking quite a lot of niggly (and hard-to-scale) code, and things would probably still fall through the gaps, but it might be a nice thing for Tumblr to do to counter the perception that it’s just about the mindless reblogging.
… but Techcrunch do. By leading his story with the default view (change in greenhouse gas emissions, 1990-2006) rather than the actual emission figures (as shown here)
Erick Schonfeld managed to construct an argument that somehow Sweden and Canada were causing more climate change than the US, despite their lower per-capita emissions (and of course far lower populations). He went on to ignore (and ridicule) comments pointing this out, despite being the sort of site you’d expect to champion the idea that the audience might know better. (via gilest)
Ben Ward’s call to stop interacting with TechCrunch - and both its major editors - makes more sense all the time.