Yesterday the Greater London Authority published the 2018 edition of our annual Housing in London report, which acts as the main evidence base for the Mayor’s housing policies. Over the next few blog posts I’m going to go into more detail on some selected visualisations from the report that I hope might be of particular interest.
Some of the new visualisations in the report were done in R, but the bulk of the charts were made in Excel, which I continue to be a big fan of as an accessible and flexible dataviz tool. I think the chart that compares annual rates of population and housing stock growth in various international cities is a good example:
The annual rate of population growth for each city over the most recent five years available (generally 2011-16, see below for more details) is on the X axis, while the annual rate of growth in its housing stock is on the Y axis. The size of the bubble represents the population of each city, while the colour represents its region of the world. The dotted diagonal line represents equal rates of population and housing growth: cities above it have seen faster growth in the number of homes than in the number of people over the last five years, while in cities below it population has outgrown the housing stock. Unsurprisingly, none of these cities have seen a fall in their housing stock over this period (Dublin is closest with an annual growth rate of just 0.12%).
The data for this chart was assembled over quite a long period of time by trawling national or municipal statistics sites. Cities were included if they seemed like good comparators for London and if I could find suitable data on their population and housing stock. Most of them are fairly large cities – the two smallest are Vienna and Dublin, included because Vienna is often seen as quite advanced in terms of housing policy and because Dublin is a close neighbour of London’s, an extreme case of unresponsive housing supply, and my home town.
I would have liked to include some Chinese, Latin American and African cities but couldn’t find the right data. For cities that have a significant amount of informal housing I imagine official housing stock measures become less meaningful, anyway.
More broadly, if anyone can point me towards good data sources for any other cities I’d be happy to try and include them. At some point I also intend to put together and share a single dataset of population and housing stock observations for as many cities and as many years as possible.
Edit: You could legitimately criticise the kind of comparison made in this chart on the grounds that population growth is not exogenous to housing growth – fewer people will come to the city (or more will leave) if there isn’t enough housing to go around. This might be a particular issue in cities with lots of rent control, which limit the flexibility of the market to respond through over-occupation. I sympathise with that line of argument, but in the absence of any more widely adopted measure of demand or of comparable data on rents, I think population growth is probably the best thing to use for now when making international comparisons.
As I said above the data gathering was largely opportunistic, which in practice means that many of the figures, particularly for housing stock, relate to administrative city boundaries rather than any more theoretically sound or comparable boundary such as ‘functional urban area‘. The upshot is that in most cases the metropolitan area spreads beyond the boundaries of the city as defined here, with Barcelona the main exception as it is measured as the province, which has a population 5.5 million, rather than the functional urban area which the OECD says has a population of 3.8 million in 2014. Tokyo is at the other extreme, with these figures relating to its prefectural population of 13 million rather than the Greater Tokyo population of 36 million. For some of these cities it should in theory be possible to produce housing stock figures to the functional urban area boundaries using Census data for small geographies, which would enable some comparison of distributions within those boundaries.
City data sources
The sources used are below, including the definition of the area used. If anyone knows of any issues with these sources or any better options please let me know, either with a comment here or with an email to email@example.com.
- Barcelona (2011-16): Housing data from Gobierno De España, Ministerio de Fomento – Estimación del Parque de Viviendas (estimated housing stock); Population data from Instituto Nactional de Estatistíca – Cifras oficiales de población. Province of Barcelona.
- Berlin (2011-16): Amt für Statistik Berlin-Brandenburg – Wohnbestand in Berlin (Berlin housing stock); Melderechtlich registrierte Einwohner (registered residents). Berlin city-state.
- Dublin (2011-16): Central Statistics Office Statbank – Housing Stock and Vacancy Rate 1991 to 2016, and Population Change 2006 to 2016. County Dublin.
- Hong Kong: Government of the Hong Kong Special Administrative Region, Census and Statistics Department – Hong Kong Annual Digest of Statistics 2017, Stock of permanent quarters by area and type and Mid-year population. Hong Kong SAR.
- Lisbon (2011-16): Statistics Portugal – Resident population and conventional dwellings. Lisbon Metropolitan Area.
- London (2011-16): Housing data from Ministry of Housing, Communities and Local Government – Housing live table 125; Population data from Office for National Statistics – Mid-year population estimates. Greater London area.
- Madrid (2011-16): Data sources identical to Barcelona but the area covered is the Comunidad de Madrid (Autonomous Community of Madrid).
- New York (2011-16): NYU Furman Centre – CoreData.nyc, using data from the American Community Survey. New York City.
- Paris (2009-14): INSEE – Statistiques locales [NB this link now has data for 2010 and 2015, but when the report data was compiled it had only 2009 and 2014]. The area used is the City of Paris plus the ‘petite couronne’ departements of Hauts-de-Seine, Seine-Saint-Denis and Val-de-Marne.
- Seoul (2011-16): Seoul Metropolitan Government, Statistics by Category – Population Trend (resident population); Number of houses by type of housing unit. Seoul special city.
- Singapore (2011-16): Ministry of Trade and Industry, Department of Statistics – Number of residential dwellings and Total population by residential status. City-state.
- Sydney (2011-16): Australian Bureau of Statistics – 2011 and 2016 Censuses of Population and Housing (private households only). Sydney Urban Centre.
- Tokyo (2008-13): Statistics of Japan e-Stat Portal – Japan Housing and Land Survey Results for Prefectures (Prefecture, Shi, Ku, Machi and Mura), 2008 and 2013. Housing data is from Table 1 and Population data (household members) from Table 2. Tokyo Prefecture.
- Toronto (2011-16): City of Toronto, City Stats in Detail – Census 1996 to 2016. Toronto City (excluding the rest of the Greater Toronto and Hamilton Area).
- Vienna (2011-16): Stadt Wien – Bewohnte Wohnungen (inhabited homes); Population. City State.