I think another element of this discussion is whether the income is planned for or not. Rapid changes are what get ya...
To go from $60K + -> $14K in a year would be very hard, mainly because investments have already made, be they student/consumer debt, cost/type of house purchased, number of children, area lived in, job/career choices, etc. Frankly, because of choices made up to now, we could not live on $14K a year without resorting to bankruptcy, because even rapid downsizing costs money. Heck, even moving to a cheaper rental costs money - gas for the car, boxes, security deposit, etc..
In our case, as I mentioned before, when I was a single student living in London, I lived on $14K a year. While London is a very HIGH COL location, it is also a great place to be a starving student - lots of cheap digs, cheap student union pubs for cheap beer, and everyone is poor so there is no pressure to spend lots.
The other thing too is that the *choice* to live on $14K a year is a privilege. My ex-boyfriend right after college was all proud of himself for living on under $8K a year by living in a squat. My mom (who grew up dirt poor) ripped into him one day for comparing himself to the poor families he lived next to because as she said "did you ever ask those families if THEY have chosen to live like this? Because, Mr. Ivy League educated, white upper middle class man, you can leave whenever you get tired of it. And they can't."