cross-posted from: https://lemmygrad.ml/post/3768443
Researchers estimate that each additional centimeter of height is associated with a 1.30% increase in annual income.
https://www.forbes.com/sites/traversmark/2020/04/16/your-height-has-a-big-impact-on-your-salary-new-research-seeks-to-understand-why/
Yes. And usually these factors are controlled for when picking your study's sample.
https://www.statisticshowto.com/matched-samples/
"All factors held equal" doesn't mean the different factors are equal in effect, just that the sample is chosen such that the other factors are identical across the two groups.