Maybe Callithump, you could also translate this as "a wold wide joke" if there an equal to "world wide" in Chinese. Because this settling for less with the same personal capacities is a world wide phenomenen.
Maybe the "cosmic joke" in the end is on the one whe grabs the dubble income. Those who settle for less can do so for a purpose and have different reasons for it.
Quality of life, staying level with and loyal to the social circle they were born to. (or to explore life rather than their bank account).
There are many people who do not have the urge to be richer than their neighbours.Who want to share.(That's what allows the very rich to become so grabbish).) (The law of nature occured to me only because I thought of the inevitable connection: where people settle for less other's can settle for more)
The "cosmic" problem ( or just another and cruel "cosmic joke"? ) is that the larger part of the world does not have the choice to settle for less , because it's quite impossible to settle for less than nothing if you want to stay alive.
Is "world wide" another option?