Have you heard of Sam Vimes “Boots” theory of socioeconomic unfairness, often called simply the boots theory? Sam Vimes is a protagonist in many of Terry Pratchett’s Discworld novels.

The reason that the rich were so rich, Vimes reasoned, was because they managed to spend less money. Take boots, for example. … A man who could afford fifty dollars had a pair of boots that’d still be keeping his feet dry in ten years’ time, while a poor man who could only afford cheap boots would have spent a hundred dollars on boots in the same time and would still have wet feet.