This math is seriously incorrect. It is incorrect because there are disasters which can’t be predicted, and those which come with various types of warning signs. This is the right math for events like floods or earthquakes that give very little warning. For events like political upheaval, there are warning signs.
Most corporate risk analysis professionals don’t predict based on historical frequency, they predict based on indicators. This is true. But the risk analysis professionals who are predicting based on indicators have the chance much higher than my calculation. See the New Yorker piece referenced at the beginning of this article:
Game Theory on the “Second Civil War”
A Strategic Path to Avoidance Flows from Analyzing Outcomes (also we trash on Vox a bit)
According to the consensus among that particular set of experts, the current media and social climate has made a violent revolution against the government 7.3 times more likely than “normal,” on an average annual basis.
This here depends on the outlay:
When preparing for such events, the best course (by a huge margin) is to instead invest the money you would spend on disaster prep and watch it grow exponentially.
The outlay for buying a rifle and two cans of ammo is approximately $1000. The outlay for several months worth of rice and a rain barrel is probably several hundred more.
Then, when the warning signs come, you have 10x or 20x the money to spend on disaster prep.
This is bad analysis. See, for instance, Chile right now. The country went from “higher subway fare in Santiago” to “troops in the streets” in the span of a week, and all the banks immediately closed, as well as most of the grocery stores. You do not see these things coming. If people could see them coming then they wouldn’t happen.
Work out the probability tree. Things like buying supplies and weapons can be done on a week’s notice.
Until there’s a run on them, or the government prohibits the sale of them, both of which are tremendously likely. If something like that happens here, guns will become the most scarce and valued commodity in the country in the span of about 24 hours.