August 5, 2015

What’s in a browser language default?

Ok, so this is from Saturday and I hadn’t seen it until this morning, so perhaps it should just be left in obscurity, but:

Claims foreign buyers are increasingly snapping up Auckland houses have been further debunked, with data indicating only a fraction of visitors to a popular real estate website are Asian.

Figures released by website realestate.co.nz reveal about five per cent of all online traffic viewing Auckland property between January and April were primary speakers of an East Asian language.

Of that five per cent, only 2.8 per cent originated from outside New Zealand meaning almost half were viewing from within the country.

The problem with Labour’s analysis was that it conflated “Chinese ethnicity” and “foreign”, but at least everyone on the list had actually bought a house in Auckland, and they captured about half the purchases over a defined time period. It couldn’t say much about “foreign”, but it was at least fairly reliable on “Chinese ethnicity” and “real-estate buyer”.

This new “debunking” uses data from a real-estate website. There is no information given either about what fraction of house buyers in Auckland used the website, or about what fraction of people who used the website ended up buying a house rather than just browsing, (or about how many people have their browser’s language preferences set up correctly, since that’s what was actually measured).  Even if realestate.co.nz captured the majority of NZ real-estate buyers, it would hardly be surprising if overseas investors who primarily prefer to use non-English websites used something different.  What’s worse, if you read carefully, is they say “online traffic”: these aren’t even counts of actual people.

So far, the follow-up data sets have been even worse than Labour’s original effort. Learning more would require knowing actual residence for actual buyers of actual Auckland houses: either a large fraction over some time period or a representative sample.  Otherwise, if you have a dataset lying around that could be analysed to say something vaguely connected to the number of overseas Chinese real-estate buyers in Auckland, you might consider keeping it to yourself.

avatar

Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »

Comments

  • avatar
    Steve Curtis

    The background to this is websites are very interested in clicks and where they are coming from. Its interesting that they are going deeper and getting language settings of the browser as well.
    Does ethnicity depend on your language settings now?

    2 years ago

    • avatar
      Thomas Lumley

      Presumably it’s the other way around: language settings are influenced by ethnicity.

      2 years ago