A 2014 study by Stanford academics Edward Lazear, Kathryn Shaw and Christopher Stanton set out to establish how, and by how much, supervisors enhance worker productivity.

And at the risk of minimising their excellent study to only one key point . . . this is the snippet from their research that I was most taken with:

Replacing a boss who is in the lower 10% of boss quality with one who is in the upper 10% of boss quality increases a team’s total output by more than would adding one worker to a nine member team.

A seemingly small margin; a massive improvement and effect.