This is Part 1 of a tutorial series on the nonadditivity of correlation coefficients. We demonstrate why it is not possible to arithmetically add, subtract, and average Pearson’s r or Spearman’s rs.
The article is available at
07-04-2017 update: In page 1 the line for the Beta1 should read “is the slope of a simple linear regression model”. My fault. Fixed today along with few other nuances.