NASA has a fair amount of money that they don't know how to waste....so they paid up some guys to think about the collapse of western civilization. Yeah, I know....you'd think they'd waste it on meteor research, the chances of aliens arriving in Montgomery, or how to sustain life on Mars.
What they got was a decent report concluding that we need regulation in some form....to reduce economic inequality (wealth redistribution) and rules to preserve natural resources (mostly because of climate change). Yeah, this doesn't really fit for NASA but I'm guessing some idiot wanted to help hire up some PhD guys with time on their hands and no pontoon boat on the lake.
They concluded in this study that two important features came up every time that a society came near to non-existence (Romans for example). First, they always tended to waste resources. Second, they tended to have some split in society where some folks had much and some folks had much less. The elite crowd grew, and the others got hostile.
Generally, when societies came to a conclusion.....they tended to have idiots who finally got to the top and really screwed up priorities. Taxation, expenditures, and continued war efforts....usually drain empires enough.....that they collapse when the first minor issue occurs. You can talk about wealth redistribution all you want.....but when guys sit around with idle hands and hungry stomachs.....they tend to argue, get into single dimensional issues, and always want someone to fix their problem. Fixing usually means twice as much is wasted in the end.....and everyone whines about the solution....more than the problem.
The sad thing here is that NASA paid a couple of PhD guys to conclude this. I would have done it for them....for a bucket of fried chicken, some Pabst Blue Ribbon, and ten bucks. I'm guessing that NASA wasted a good bit more than that.