@Mr_Mister @Tfmonkey
It seems was a chain mail from the early 2010s and the study never happened in a practical environment. They tried but was never allowed, after all disproving socialism is a no-no.
https://danieljmitchell.wordpress.com/2011/11/16/does-socialism-work-a-classroom-experiment/
https://www.macrobusiness.com.au/2011/12/myth-of-the-socialist-classroom-experiment/