Basically, "economical" means "with minimal waste and maximal efficiency". Thus, the phrases "wasteful economy" and “economic inefficiency” are oxymoronic. They are also the very foundation of the modern “equity” concept.
[For those unfamiliar with the “equity” concept, imagine that you and your spouse share the entire world with just a single gangbanger named Mohammed Jackson and his n “lady friends” (baby-factories in vivo). World population: 2+1+n.