Stacked bar chart

A recent article in The Economist discusses the spread and possible future struggle of Amazon and Alibaba. Many countries offer room for growth.

This is an excellent example of a stacked bar chart. It avoids common problems.

The bars sum to 100%, so their heights are uniform and comparison is easy. With only 3 categories, there are not too many labels or tiny bars.

The messages are clear. In India and China, many people are not yet online. In every country except India, a strong majority of people online are shopping there.

Log scale

Bitcoin is a major phenomenon of out time. There is nothing like very rapid growth to generate excitement.

As is often the case, this linear scale plot obscures rate of change and the small early values. It is worth also looking at a log scale plot.

The early adopters had the best earning potential.

Some people talk about the promise of bitcoin as the new money. Of course this price history shows that it would have been amazingly deflationary. Hardly a good thing.

The price of bitcoin is financial, but its cost is environmental. “Mining” bitcoin takes a huge amount of electricity, and the major mining countries rely heavily on coal fired power plants.

The scale of this electricity consumption can be compared to countries.

The choice of a bar chart is appropriate, as is ordering the countries so that the longest bar is at the bottom, nearest to the scale. The small drop shadows, however, only add blur.

Meaningless bar chart

In October 2017, the Council of Economic Advisers, an agency within the office of the President, released a report on the effect of a proposed corporate tax cut on wage growth. It was not widely praised. The report predicts that:

“Reducing the statutory federal corporate tax rate from 35 to 20 percent would, the analysis below suggests, increase average household income in the United States by, very conservatively, $4,000 annually.”


“Using 2016 household income as the baseline, these effects translate into an increase in average household income from $83,143 in 2016 to between $87,520 and $92,222, an increase of $4,000 to $9,000 in wage and salary income alone. (See Figure 2.)”

The bar chart in Figure 2 clearly and compellingly shows that 9000 is more than twice as big as 4000. The competition is strong, but this is clearly a candidate for dumbest graph of 2017.

One of the basic guidelines in graph design is that the quantity axis of a bar chart should include zero. In this case, that means plotting income and changes. If a bar chart is needed, it should look more like this.

The predicted increases are 5 and 11%. The authors do not state when the income increase will be fully achieved, but the report suggests 7 years out. This would correspond to annual growth of 0.6 to 1.3%, similar to the 1.1% average rate that occurred from 2008 to 2016.

Perhaps the authors are asserting that the income growth rates would add so that the total would be about 2%. That is a growth rate not seen since 1974, when the corporate tax rate was much higher.

Who are these people? Is that the best they can do for justification?One hint is the the Chair is Kevin Hassett, perhaps best known as the co-author of Dow 36,000 in 1999.