Joe N, a longtime reader, tweeted about the following chart, by the People's Policy Project:
This is a simple column chart containing only two numbers, far exceeded by the count of labels and gridlines.
I look at charts like the lady staring at these Ad Reinhardts:
My artist friends say the black squares are not the same, if you look hard enough.
Here is what I learned after one such seating:
The tiny data labels sitting on the inside top edges of the columns hint that the right block is slightly larger than the left block.
The horizontal axis for time is reversed, with 2019 appearing after 2020 (when read left to right).
The left block has one month while the right block has 12 months. This is further confused by the word "All" which shares the same starting and ending letters as "April".
As far as I can tell, the key message of this chart is that the month of April has the impact of a full year. It's like 12 months of outflows from employment hitting the economy in one month.
My first response is this chart:
Breaking the left block into 12 pieces, and color-coding the April piece brings out the comparison. You can also see that in 2019, the outflows from employment to unemployment were steady month to month.
Next, I want to see what happens if I restored the omitted months of Jan to March, 2020.
The story changes slightly. Now, the chart says that the first four months have already exceeded the full year of 2019.
Since the values hold steady month to month, with the exception of April 2020, I make a monthly view:
You can see the slight nudge-up in March 2020 as well. This draws more attention to the break in pattern.
For time-series data, I prefer to look at line charts:
As I explained in this post about employment statistics (or Chapter 6 of Numbersense (link)), the Bureau of Labor Statistics classifies people into three categories: Employed, Unemployed and Not in Labor Force. Exits from Employed to Unemployed status contribute to unemployment in the U.S. To depict a negative trend, it's often natural to use negative numbers:
You may realize that this data series paints only a partial picture of the health of the labor market. While some people exit the Employed status each month, there are others who re-enter or enter the Employed status. We should really care about net flows.
In all of 2019, there were more entrants than exits, leading to a slightly positive net inflow to the Employed status from Unemployed (blue line). In April 2020, the red line (exits) drags the blue line dramatically.
Of course, even this chart is omitting important information. There are also flows from Employed to and from Not in Labor Force.