Skip to main content
Cross Validated

You are not logged in. Your edit will be placed in a queue until it is peer reviewed.

We welcome edits that make the post easier to understand and more valuable for readers. Because community members review edits, please try to make the post substantially better than how you found it, for example, by fixing grammar or adding additional resources and hyperlinks.

4
  • 8
    $\begingroup$ Note that you don't have to look at averages for Simpson's paradox to occur--just don't tell the model there are four groups. In addition, although it might be nitpicking, the fit in the lower plot is not very convincing, since it looks like it assumes all slopes to be equal, which you can clearly tell isn't the case. $\endgroup$
    – Frans Rodenburg
    Commented Mar 3, 2020 at 5:39
  • 2
    $\begingroup$ As elsewhere in this this thread, mixing red and green is problematic for many readers. For anyone challenged by this colour choice, the graph shows four slightly overlapping clusters each summarized by upward sloping lines, whereas the whole dataset shows a negative relation. $\endgroup$
    – Nick Cox
    Commented Mar 3, 2020 at 12:04
  • 2
    $\begingroup$ Agreed Frans, taking averages is an over-simplification, as is the slope on the bottom graph. In fact, I believe both graphs are purely fictitious representations of the concept. They came from the last link in my answer, which was linked to from a different article I was reading that illustrated Simpson's paradox in an econometric setting: Tax Burdens, Per Capita Income, and Simpson’s Paradox $\endgroup$
    – TH58PZ700U
    Commented Mar 3, 2020 at 21:41
  • 1
    $\begingroup$ That's either very few or very many bedrooms! :) $\endgroup$
    – smcs
    Commented Mar 4, 2020 at 15:39