The Shapes of Cities

For a long time, I've been interested in the shape of cities and I suspect that if you're reading this you might be similarly afflicted. By 'shape' I mean their political boundaries as opposed to their general urban footprint. The latter can be seen by driving around or from a plane window, particularly when it's dark, but the political boundaries are much less obvious. This is particularly true of US cities. Take Houston, Texas - the first example below. 

The boundary of the City of Houston - Google Map

Look closely at this and - at least if you're not used to the political geography of American cities - you might be very confused by this fragmented, segmented mess of boundaries. Then go to Google maps and try different search terms, such as 'city of los angeles' or 'city of columbus' (Ohio) and you'll soon discover that Houston isn't that unusual at all. Try it for other cities and you'll see what I mean. Columbus, Ohio is a particular favourite of mine as I know it quite well having lived there for a couple of years in the early 2000s.

City of Los Angeles - Google Map

City of Columbus (Ohio) - Google Map

These unnatural-looking boundaries are the result of a complex mix of geography, history and politics that have real impacts on the ground. From education and transport to housing and waste management, the shapes of cities really do matter in this respect. Of course, this is a much-studied topic in urban studies, not least by Professor John Parr of the University of Glasgow. In Parr's economic definitions of the city, he outlines four types - but none of these explain the kinds of boundaries we see above. One major explanatory factor in all of this, of course, is tax revenue. But I'm not going to get into that now because it opens up a whole range of other topics, including white flight, suburbanisation, and schooling, amongst other things. The point is that the 'shapes' of cities are not accidental and who is included or excluded is inherently political. 

In the United Kingdom, we might not have such unusual city boundaries, but the political geography of our cities is far from perfect - perhaps one reason for the resurgence of the 'city-region' concept over the past decade or so. When we're talking about urban economies, it makes much more sense to think about the functional urban area than it does to use data associated with an arbitrary political shape. This is as true in the US as it is in the UK. The example below shows that the City of Atlanta has less people than the City of Liverpool and that it's only slightly bigger in scale. But anyone who knows anything about these places will understand that 'Atlanta' is much bigger than 'Liverpool and is vastly more sprawling, with a metropolitan population of around 5.5 million compared to less than a million in 'Liverpool' (by one definition). 

Atlanta vs Liverpool - which is bigger?

These kinds of issues are part of the reason organisations like the Centre for Cities use the Primary Urban Area definition of cities for the 64 largest urban areas of the UK. In a recent study, I used a definition developed by Geolytix which is based on the 'sprawl' of the urban area rather than political boundary and found this to be a much better fit than the administrative area. When conducting comparative analyses of cities, we need to ensure we are comparing like with like, and using a functional definition often helps avoid the kinds of underbounded/overbounded problems that arise when (e.g.) comparing places like Manchester and Leeds. The former is normally said to be 'underbounded' because the functional urban area is much bigger than the local authority area of the same name and the latter is said to be 'overbounded' because of its much wider local authority area, which extends beyond the core urban fabric. For a comparison of UK 'city' sizes, see this graphic I produced a few years ago:

All cities shown at the same scale

Surely there's a point to all of this? 

Yes, glad you asked...

For planners, politicians, residents and neighbours, the shapes of cities matter enormously. It might dictate which school your children can go to, whether your local facilities are well funded, whether you have a well-functioning local transport system, when your bins get emptied, how many pot-holes you have in your street and all sorts of other things. But let's not get into that now. Instead, I'll end with another city shape, this time for the City of Detroit (one of my favourite cities, but much-maligned).

Detroit - 8 mile boundary line to the north

Can Google search data predict an election victory?

Today seems like a good day to write a little blog post on what search data can and cannot tell us. Why? Because of the story below, which has been on the front page of the MailOnline for much of the day. This is just the way news works, but I thought it would be useful to give a bit more information here. The story behind the story goes something like this...

Simon Rogers, datajournalist and Data Editor at Google in San Francisco, got in touch some time in April to ask if I could help him map party leader search patterns by constituency. I'd been doing a lot of work with search data for housing markets anyway so this seemed like an interesting idea. We took search data for all points that were geocoded (there were about 5,000 total across the UK) and then produced a constituency version for all 650 seats. The final constituency results matched very closely the proportions for the individual places. The data are for the previous 12 months. 

MailOnline front page 07/05/15

The big question is what this all means. Do I think, as the MailOnline suggest, that 'Google Search tips Cameron to win election'? No. Do I think it disproves it? No. Do I think the large volume of search for Nigel Farage indicates his level of popularity across the country? Again, no. However, it could indicate that people are more likely to show interest in UKIP in an environment when nobody else is watching or listening. But we don't know. Does this prove that Miliband will come third? Definitely not. The map merely indicates who was the most searched for party leader in each constituency. The intent and sentiments of individual users are not known. In my own research in housing market analysis I've tackled this by doing interviews with website users but since this data is from Google they could of course add in other terms which people might combine with party leader names (some more favourable than others!). 

Kate Newton from Bing also got in touch to say they had worked on something similar (though much more sophisticated) in relation to the Scottish Independence referendum last year. More widely, there is a body of emerging research (including my own) which looks at search patterns and subsequent activity - mostly in the field of economics. The results suggest that search can be analysed meaningfully to predict future activity. But that's not what the party leader piece was about - not from my perspective. Thankfully, other media outlets were more measured in their analysis - such as BuzzFeed UK, The Scotsman,  and The Telegraph. 

MailOnline story 07/05/15

What's most interesting to me? Well, I'm most interested to see how the search patterns relate to outcomes in key marginals. I suspect there will not be much of a pattern but if there is it will be interesting to attempt to take this little piece of work further - perhaps for the US 2016 election. Other than that, this is an interesting stocking filler on a day when the papers and TV crews are forbidden from reporting anything really substantial until the polls close at 10am. In the meantime, my favourite snippets from the search map...

David Cameron is the most searched for leader in his own constituency, but he's surrounded by a sea of purple, plus a blob of red and orange.

Witney - David Cameron's constituency

Perhaps a little predictably, there is a lot of search for UKIP in Kent but - strangely - it appears that in the constituency where Nigel Farage is standing (Thanet South) the party leader most searched for is Ed Miliband.

UKIP - lots of search in Kent, but not to much in Thanet South

The search results produce some interesting results. The image below is a good example. Natalie Bennett (Green Party) is the most searched for leader in Durham North West and next door in Durham North the leader (by search over the past 12 months) is Leanne Wood (Plaid Cymru). I suspect this was down to a localised spike in interest after the leaders' debates.

Durham - Green and Welsh Nationalist stronghold?

Other interesting nuggets to emerge were the way in which geographical patterns sometimes reflected the opposite of what you'd expect. The most obvious example was where Nicola Sturgeon (SNP and not standing in this election) was the most searched for party leader in several English constituencies, such as Chesterfield (below). Her excellent performance in the leaders' debates probably led to a spike in interest. Perhaps the SNP ought to consider putting up candidates in England too.

The SNP take Chesterfield? Not so fast.

A kind of similar situation to the SNP/Chesterfield example can be seen in the final image below, where Nigel Farage is the most searched for leader in Aberdeen North. This Scottish constituency has no UKIP candidate and, even if it did, they would be a long way away from the top party.

What's my prediction for the outcome of the election? The only prediction I'll make is that the results will look nothing like this map!

Interpreting political maps

I recently tweeted a couple of maps showing the 100 most and least deprived constituencies in England. I used the 2010 English Indices of Deprivation to calculate this, aggregating the data from smaller areas to parliamentary constituencies. The method is not perfect but on the whole the areas identified are either among the poorest or richest in England. There are 533 constituencies in England so the figure of 100 is roughly the 20% most and least deprived (18.76% to be more precise). I shaded the maps using red for Labour, blue for Conservative, Yellow for Liberal Democrats and so on. The most obvious thing about the maps is, of course, the fact that the most deprived map shows nearly all Labour constituencies and the least deprived shows almost all Conservative constituencies. Click the caption below the images to see interactive versions.

100 most deprived constituencies

100 least deprived constituencies

These kinds of maps often make a big impact and are shared widely but people tend to draw conclusions from the patterns they see that are not necessarily correct - and often conclusion which mirror pre-existing biases and perspectives. For example, some people see these maps and claim that voting Labour makes you poor or that only rich people vote Conservative. Some would even claim that this proves that Labour has failed the constituencies they serve. Opponents would argue that coalition cuts have merely deepened spatial inequalities and hit Labour-voting areas hardest. This is all a bit dramatic, but you don't have to search online long to find such views.

Other people might say that if you want to be richer you should vote Conservative. Other people would tell you not to be so simplistic and point to the way in which voting patterns are formed at the local level. Still others might point to the longstanding economic differences between north and south in England and say that this has something to do with it. Perhaps others will say that the Conservatives are the party of the rich and that Labour are the party for the poor. There are varying degrees of truth in all these views but the point I want to make here is that none of this can be proven just by looking at a political map.

For me, such maps are a starting point for a conversation about what these patterns might mean, whether they are a problem and what might be done about it, if anything. I'm not making these maps because I'm pro-Labour or pro-Conservative or because I think that they prove anything in particular but because I want to draw attention to the patterns and what they might mean. Finally, some observations from the maps...

• There are no Labour constituencies amongst the 100 least deprived in England.
• There are 2 Conservative constituencies amongst the 100 most deprived in England.
• Sheffield Hallam (Liberal Democrat, Nick Clegg) is amongst the 100 least deprived constituencies in England. 
• There are 5 Liberal Democrat constituencies amongst the 100 most deprived in England.
• There are 7 Liberal Democrat constituencies amongst the 100 least deprived in England.

It will be very interesting to see how these patterns change (if at all) after the General Election this year.