Doing Business Subnational - Step Graph
This case study shows the importance of following simple principles of data visualization and keeping things simple for a richer display of information. The updated graph is of a fictional country with fake data.
Subnational Doing Business reports capture differences in business regulations and their enforcement across locations in a single country. They provide data on the ease of doing business. One of the main ways in which they present their data is the "step graph" that shows both the cost and time of each procedure to set up a business. The team members use the graph above, but are aware that their audience takes some time to understand its meaning. They were looking for a way to make it clearer while losing none of the information.
The main improvement was to remove the second vertical axis and put the time variable on the horizontal axis. Left to right is a natural way of showing time, one the audience expects and understands intuitively. So-called "double axis" graphs are tricky because the audience is tempted to draw conclusions from the interaction of the two lines where there is none.
The graph now displays each procedure on the vertical axis, integrating the text into the graph. For each procedure, a full rectangle shows time and cost simultaneously. Long lines imply a lengthy procedure; tall lines imply a costly procedure.
On each axis, instead of using a regular interval for the tick marks, we marked the exact data point, removing the effort to figure out the exact numbers.
We adjusted the title and added an annotation directly on the graph to make the conclusions clear and drive the conversation around the data. The original graph referred to "numerous procedures", which was vague, and to "five agencies" that were not shown on the graph.
The result is a graph that is easier to understand yet holds more information than the original. Subnational Doing Business is already using the updated design internally and plans to deploy it in its reports in 2014.