Right now it doesn t make sense to me It says Strong Pareto Optimum is a movement from one allocation to another that can make at least one individual better off and a Weak Pareto Optimum WPO satisfies a less stringent requirement in which a new allocation is only considered to be a Pareto improvement if it is strictly preferred by all individuals Surely being strictly preferred by all individuals is a more stringent outcome than being strictly preferred by one individual Or am I misunderstanding what strictly preferred means