Endogenous selection bias

“More beautiful actors are less talented”, in the subset of actors who are selected. Because both acting talent and beauty affect the selection, if we examine those who are selected, there tends to be a negative correlation between beauty and talent.

• Endogenous Selection Bias: The Problem of Conditioning on a Collider Variable
  • https://twitter.com/bjoseph/status/1285387552837431296
  • We should be cautious about associations of patient characteristics with COVID-19 outcomes that are identified in hospitalised patients