Jared Diamond 

Assaf Wodeslavsky you could fit the entire population in the world in the state of New Jersey the overpopulation theory is based on a capitalists society during an age of technologies that are eliminating the human workforce, example 40acres and a mule in 1875 sustained a farm family of 4 to 6 today 15,000acres and a GPS guided tractor sustain the same number today 4 to 6 societies that collapse usually last no longer than 250 to 300 years there are 7 cycles that the collapsed societies all share but the best example to compare to the decline of western civilization is the Roman Empire for one we know more about their fate, we are seeing a note for note cover song comparison to Them

Assaf Wodeslavsky there has only been one society that has collapsed due to a single cause and that is debatable, the dinosaur society it collapses due to cosmic natural causes! Lol but overpopulation won't be the single cause, the rabbits and the coyotes theory when the rabbit numbers rise the coyote families do well all the pups love grow up and have litters of their own their numbers climb meanwhile rabbit populations decrease too many coyotes bad for the rabbit families but the rabbits hasn't gone extinct has it the roles reverse the coyotes with not enough rabbit to feed themselves numbers plummet until the roles reverse again, this is the only flaw I see in diamonds theory Mother nature will always find a way frogs and alagators can change sexes if need be, my point life cannot be contained and societies rise and fall but this process has been going on for who knows how long everything that is a carbon based lifeform even on a meta physical level rise fall repeat or we wouldn't still be here the only differences in the society's that have been going on for 1000s of years are many multiple factors but most are from breaking the rules of mother nature everything moderation gluttony.and greed will collapse this society