Pareto Efficiency and Optimality
This page is messed up.
 While there is a relationship between Pareto Optimality and Pareto Efficiency,
 they are different results.  I use Pareto optimality in my consulting, see also
Wiederhold, Gio: "What is Your Software Worth?"; Communications of the ACM, Vol.49 No.9, Sept.2006, p.65-75.
Some statements under P. Efficiency belong under optimality, as most of the first paragraph.  
Pareto Optimality deserves its own page. But now it redirects, and I don't know how to change that.