i think for a small % pot will have a positive impact, but in general there is a reason it is considered a recreational drug. If you put 1000 linux kernel developers in a stadium, do they do better work sober, or if the stadium is hotboxed with some exotic kush. (maybe 5%, 10% see gains... but does the majority receive buffs to their concentration, analytical skills and memory?)

Maybe the question has a different outcome if you're measuring a stadium full of Designers with Adobe Illustrator open, trying to brainstorm how a logo looks?