I'm going to answer this, thinking Johnny really is looking for the answer (silly me)
I think what they mean is that people have money after the necessities are purchased. If you look at the early 1900s, many of those in the U.S. (at least can't answer for other places), were spending simply to put food on the table, and mainly filler foods (lacking meat, healthy vegtables, etc.).
Although people are trapped by thier bills today, for the most part, they are self chosen. Necessity is food, , a roof over your head, and utilities (elec, nat gas, water). To own a car, gassing it up, insurance, eating at fast food, watching movies, cell phones, etc. is not seen as a necessity.
you probably know this, and were just taking a piss........