You can be pareto optimal / efficient without a everyone having a 1/n share. The idea of optimization is that everyone gets the best possible set. E.g. Alice

You can be pareto optimal / efficient without a everyone having a 1/n share. The idea of optimization is that everyone gets the best possible set. E.g. Alice prefers tomatoes, Bob prefers mangos. Thus, Alice ends up with 100% of the tomatoes, Bob with 0%. Unfortunately it's mostly the externalities and irrationality / wrong assumptions that fail us. An economy is not optimal (or pareto efficient) iff people are disproportionally sick, sad and angry because of economical reasons (and don't trade this sickness, sadness and angriness for something that gives them more utility).