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Comments

Thomas

The cartogram is definitely the most truthful, but you are sacrificing a huge amount of the original purpose by having the shape be barely recognisable, right?

The point of using a map instead of a bar chart is to convey the difference in geographic areas and the Guardian one requires a good knowledge of the map of Britain and even then it's hard to work out whats going on in say, Norfolk or Monmoutshire

Kaiser

Thomas: you raised the core issue. Is the tradeoff worth it? Is it better to be accurate about geographical location and paint a distorted picture of the importance of each region to the total? Or is it better to be accurate about the importance of each region at the expense of location?

Pjie2

Is it possible to convey both by using hue for the proportion and intensity for the population? So you end up with an intense yellow dot for London, a pale blue for most of rural England and Wales, and s very pale yellow for Scotland with more intense cities?

Tim

I don't buy this idea that the last map is "barely recognisable". Okay, it isn't what Britain usually looks like on a map, but it's pretty obvious to me that the squeezed bit at the top is Scotland, which has a low population density, And I can see London which is massive, also for obvious reasons.

Absolutely the trade-off is worth it. Imagine a hypothetical nation with two regions. The much larger Region A has one resident who voted remain. The small Region B has 100 residents and 51 voted leave, 49 remain. Leave wins (51-50) but a geographically more accurate map wouldn't suggest that at all. It would suggest that a massive majority voted strongly to remain, while a small minority voted weakly to leave. That kind of map is misleading and tells us nothing.

The only reason the geographical maps above look vaguely sensible is that two largely remain voting areas, Scotland (low population density) and London (high population density), balance each other out.

Ken

Any way you present it, the only actual fact that matters is Leave won.

Antonio

There are many other possible variations. For example to take into account turnout rate and render it as opacity. See map 2 in the following article:
https://medium.com/@jakeybob/brexit-maps-d70caab7315e

jlbriggs

Tim: the purpose of showing the data on a map is to display the geographic distribution of the data.

Toward that end, the extreme distortion of geography in the cartogram fails to communicate that information very well.

There are any number of ways to go about showing the impact of population density without making a map that is no longer useful. You could plot data that is already adjusted by population, you could plot a bar chart instead of a map, you could use both a map and a bar chart together, etc.

I find cartograms to be one of the least effective ways of plotting geographic data - you remove the geography! So what's the point? If the geography is no longer encoded on the map, then a map isn't what you're looking for, IMO.

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