This phrase has again resurfaced over the last few weeks, the think tanks especially the right wing variety talk about it a lot. It is used in connection with Nations military contributions, as well, as in the sporting arena.
When a country, with a small populace, wins more Gold medals in the Olympics or other international competitions, vis-a-vis other Nations with a bigger multitude of citizens, analysts glowing state the smaller country, small refers, to size of population, in this instance, is described as punching above its weight.
This kind of meaningless analysis and comparisons have its inherent dangers and can lead to angst and alienation among the various ethnic composition of a Country. Instances a rife where television presenters and reported have been disciplined for carrying such analysis too far!
This is an inefficient phrase, I think. Presumably, this phrase originates from the Boxing code. But, the boxingcode has strict parameters and the participants have to be punch within the prescribed weights not above or below! Either, of which is considered dangerous and inefficient.