Almost as often as I see a pie chart with a hundred tiny slivers, I see line graphs using two y-axes. And it is just as bad.
Is a chart that looks like this:
…really so bad?
While “bad” is perhaps a strong word for using 2 Y-axes, Stephanie Evergreen shares some alternatives in this post that may do away with the resulting confusion. Follow the link, or check out some options below.