The Pareto principle is an economics idea - something is considered Pareto efficient if you can make someone better off without making someone else worse off, and you are at a Pareto optimum when you can't make anyone better off without making someone worse off. Of course, because "better off" and "worse off" are entirely up for interpretation, people argue that taxing the rich to improve the lives of the poor is not Pareto efficient because you're worse off if you have less money regardless of how much money you have left. So the only Pareto efficient solution is to grow the economy until all the poor people make enough money.