Hard for me not to conclude that hoarding can happen more easily now, and that it is more prevalent because it takes a surplus of money and a surplus of goods available, plus some relatively remarkable social and political stability (that the U.S. has had since the 1870s...) Other times and places haven't had the critical combination of lots of available goods plus so many people with enough money and space to store it. Go look at stories of hoarders from the 1800s, they are all very wealthy (even for the time) people.

Now, with mass production and vastly increased purchasing power, this is what we see in America. You cannot tell me that a mental health issue in places like Yemen, Syria, or Guatemala can manifest itself in the same way, because people do not have the money, available goods, or social stability for this disorder to become widespread.