This post has two parts, a commentary on the charts, and a more technical discussion on the visualization.
Recently I posted a chart on the evolution of the economy and social inequality in Argentina. The chart was a reproduction of one made by Alberto Cairo for Brasil, where it was shown that starting on the governments by Lula (in principle more leaned to the left) the country grew and inequality was reduced. The same trend can be seen in the Argentina chart starting from the governments of Kirchner and Fernandez (perhaps even from the interin Duhalde government). From the begining of this exercise my attention was drawn to the point that the trend starts around 2002 for both countries, so I thought it would be interesting to make the same chart for the countries in the region:
Here I reduced importance (by lowering color contrast) to presidential periods, so we can focus in the curve trends. As countries have very different sizes, putting them in the same chart is not super-helpful. Let’s try a separate chart for each country (now with more colours):
I think it can be well appreciated that yes, all the countries of southern south America (the southern cone as we call it in Argentina) have grown economically and lowered inequality from 2002 on. Without entering a discussion on the causes of the trend (which would require a rigorous statistical study and a good theoretical base), there are many interesting details we can see:
- Chile is the only country that has a clear and constant trend for the whole observed period, even though its Gini coefficient is higher than Uruguay or Argentina (however comparing Ginis between different countries can be tricky, it’s best to compare them when methodologies are the same)
- Paraguay, Argentina, and Brasil suffered huge swings in the late 90s.
- Bolivia and Paraguay are much smaller economically, although in the interactive version you can see that actually all of latin america is was smaller than developed countries.
I have the feeling that the charts above do not make the best job at highligting how coupled the countries are. For this purpose, I created a second chart in which I used a single color to distinguish the four combinations of larger or smaller GDP or Gini. The idea of this chart is that when countries change all in the same direction (irrespective of precise direction or size of change) it will look like a solid color block. This is the result:
I am pretty happy with the chart, the joined trend after 2002 is now very evident. I am still lingering about how to include at the same time the size of the change without loosing this strong highlight. It could be very useful, take for instance Chile that has a few bad years between 1998 and 2000, but they are actually way smaller than Argentina’s 2001 crisis–but in this chart they look the same, so bad chart, bad.
In a continuation post we shall study how to include this information as well as presidential periods in this deconstructed Cairo chart.
Having many countries together in the plot makes it complex to distinguish presidential periods — which is in my opinion what puts the original chart by Alberto Cairo in a different class than a simple connected scatter plot (maybe we can call it a Cairo chart?). In this case I lowered the colour cacophony on purpose to highlight just the direction of the curves, but in doing so I maybe should have distinguished before-after 2002? Perhaps we can plot a simpler variable like left or right leaning government? I would need to catalogue all those governments, though…(you can help in this repository).
Placing the labels in the interactive is a nightmare for which I don’t have time. Literally, I’ve had it in dreams haunting me. The charts here are heavily stylized in Illustrator, but it’s not simple to place labels automatically without putting them on top of interesting things. Map people know this too well.
Perhaps the interactive could be helped by having presidential periods come to the foreground when you hover on top? I mean, not just the label, and reduce the rest?
The multiple scales are a discussion on their own. I left a few of the best options in the interactive. The default version is the one I like the most, but it is certainly a little misleading. It is more accurate to see all curves with the same scale, but it makes it difficult to see the details in each countries trends.
The only important scale option I left behind is an isometric on both axis (same percentage change). The closest I have is the combination of seeing all curves in the same plot, and then using a reference year to see percentage change. Just by coincidence, the x axis changes about 75%, and the y axis a 60%. So, almost there.
The list of presidents I found online is not what you think for some countries like Germany (and others), that have a president (head of state) AND a chouncellor or primer minister (head of government) who is the one holding the actual power. Adding this information is easy if I can get help (and if the World bank has the GDP and Gini data)
Finally, on the direction chart: I’ve been trying small lines under the squares to denote presidents, a colour gradient instead of a single colour for each direction, and little arrows instead of a single colour block. None is too satisfying, but I think it’s worth to keep trying. Ideas?