Threat probability is a concept put forth by Jack Spirko which states that the probability of a disaster is inversely proportional to the impact scale of that disaster. What this means is that the lower the impact (personal or neighborhood) the more likely the event is to happen.
An example of this concept is that while a giant meteor striking Earth could have the greatest impact on its residents, it is very unlikely to happen in a person's lifetime. Conversely, unless you happen to die very young it is almost assured that you are going to experience the death of a loved one or job loss. While these disasters happen to many people every single day, and are likely to happen to any given individual multiple times in their life, the scope of the impact is very small, usually only to an individual or immediate family.
This concept, along with Commonality of Disaster is really a core fundamental of Modern Survivalism. Preparing for disasters with the largest scale of impact can be very daunting and keep many people from even starting. Being prepared for a job loss or a neighborhood blackout often seems much more achievable to the beginning modern survivalist. Surprisingly if you get to where you are prepared for a small disaster you will find you are well on your way to being prepared for disasters of a larger scale.
It is a good idea to sit down and identify the threats or disasters you are most concerned about. Sit down alone or with your family and friends and write down disasters you can think of. Make sure some of the most common are on there:
- Job Loss
- Death of a Loved One
- House Fire
- Medical Issues
While some people might not consider all of these a disaster, think about the impact to a family if the primary income provider in a household is in a car accident and unable to work for one, three, or six months. How will the bills get paid and who will put food on the table.
Using the concept of threat probability sort your list of possible disasters by the Impact Scale. At the top of the list put those that only affect you personally or your immediate family. At the bottom of the list are your meteors and alien invasions. Somewhere in the middle are hurricanes and earthquakes. Now look at only the first two or three things at the top of the list (and only those). What would you need to have in place for you and your family to be able to survive in those disasters come to pass. That is where you begin your preps.
Now if you were to take those larger scale disasters from the middle of your list and perform the same exercise you will realize that there is probably about a 90% overlap. That overlap in preparedness between different disasters is the very nature of Threat Probability.