October 8, 2012

Real-estate infographics

The Herald has some quite attractive interactive graphics of real-estate prices, but I’m not entirely convinced of their informativeness.  You can see any one of the numbers by pointing at it, but you can’t see two numbers simultaneously, just the binary up/down indicator.

Having a separate category for ‘basically the same’ would help, for example, Christchurch has one red and one green for both median house price and index level, but the increase in median house price is only 0.6% over a year, and the fall since last month is a relatively dramatic 5.7%.  Perhaps the intermediate colour could designate ‘increased less than inflation’, to offset the general resistance to using inflation-adjusted housing prices.

The red and green colours they chose have sufficiently different luminance than they are likely to be distinguishable even if you’re red:green color blind, which is to be commended, but I don’t really like the implication that cheaper housing is bad and more expensive housing is good.  I don’t think the Herald would use red for decreases and green for increases in the price of milk, or petrol, or health care.

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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

    “I don’t really like the implication that cheaper housing is bad and more expensive housing is good. I don’t think the Herald would use red for decreases and green for increases in the price of milk, or petrol, or health care.”

    Well put.

    11 years ago

    • avatar
      Thomas Lumley

      Interestingly, Stuff has a story in which the hidden assumption is exactly the other way around:

      The latest Massey University Home Affordability Report shows the national affordability index improved by 2.8 per cent on the three months ending August to its lowest level in 10 years.

      11 years ago