Economics: The study of human habits, particularly in the aggregate, regarding the exchange of things of value.
For the sake of discussion, let’s assume the worst. Governments collapse with the economies and utter anarchy takes over. Split out security concerns for a moment, and lets look at the collection of things we need to consider for mere survival itself. You have to breathe, eat and drink, and remove waste. You have to meet weather conditions and face all those natural threats to health which have nothing directly attributed to human decisions. Further, we invariably live in family groupings, for any number of reasons. Indeed, an isolated nuclear family has little hope of surviving in these conditions. At a minimum, you will want an extended household encompassing not less than some 20 people. The most basic fact is, you can’t do it alone for very long.
At the most primitive level, humans harvest their needs from natural sources — hunting and gathering. There will be long periods of inaction, due to the vagaries of natural supply, so storage becomes a concern. Not just keeping stuff, but keeping it from rotting, from vermin, etc. Still, such a life is very time-consuming, and invariably risky even without the interference of external human forces. You seek ways to reduce the workload and the risks.
Because we are humans, bright ideas about survival efficiency are shared and kept. Should any household produce someone particularly talented at thinking up bright ideas that actually work, that household gains a survival advantage against other households competing for the same resources. Unless most of the world population dies off with the governments and economies, you will face competition for limited resources, never mind hostilities arising from competition. Very quickly you realize specialization of skills is valuable, provided you have enough people involved. Someone who is really good at catching food animals can free up a couple of other fellows for farming, building, or whatever other tasks promote survival.
Specialization of labor creates a de facto economy — an exchange of products of labor. Provided we don’t all suffer massive amnesia, we will tend toward this sort of thing without much consideration. Inside a household, it’s instinctive someone will be in charge in some way, and bickering over whether the internal exchange is fair will be squelched. As the size of the group grows, this becomes increasingly difficult to mediate. At some point, the whole settles into a routine, out of some instinct, of discerning the relative valuation of contributions based on how much more do we want of a given product of labor, and how much we are willing to sacrifice to get it. That’s the old “supply and demand” stuff at it’s most basic level.
To survive a meltdown to any degree, you will have to discern opportunities to supply a human need or want, in an environment where you can get something back you need or want. Minimizing artificial concerns which might tend to prevent your adaptation, your acceptance of tasks which produce value but are not in your comfort zone, is an adjustment only you can make. Ridding yourself of fantasies regarding your ability to create a demand which does not exist, forcing people to accept and trade for what you would rather produce with your time, could become the most burdensome adjustment you’ll have to make.
The luxuries we once valued will become dim memories as we struggle to get the bare essentials lined up. If in your daily existence up to now, you have closed off opportunities to develop skills and talents suitable for such dire conditions, you will have a very hard life. It may be a very short one, because we can’t ignore security concerns for very long. Indeed, should things change a great deal very quickly, a primary vocation of value would be providing security. It would help a great deal if people can adjust quickly their notions regarding legitimacy of authority as is commonly perceived today. Instead, consider what you can actually do or not do without painting the issue as one of sacred trust, and forsaking the civil religion which subtly infuses our Western world. Whether someone is “duly elected” or “duly appointed” means nothing when they come to take your stock of food. What matters is whether they can actually offer enough force to carry it through. Civility and trust between humans is a necessity for life, but slavish reverence for “government” is a senseless luxury. I assure you neither the government itself, nor your competitors in survival, will find themselves restrained by such reverence.
While it would be useful to gather physical property which will enhance your chances of survival, you’ll be guessing at best. Nobody but God can tell you how bad it will be. Just the question of whether electric power will remain available is wholly unpredictable, with the probabilities shifting daily as we observe the fireworks of social collapse. Should things really go too far, just keeping a few scraps of your private holdings may become a monumental task. However, in a very broad sense, mere conceptual property will not help you — stacks of paper with numerical values associated based on some imaginary scheme, not to mention even more imaginary electronic data in some computer somewhere. You know, bank accounts, paper currency, deeds of ownership, etc. The system which makes those things valuable is already coming apart. To the degree you have any hope it all, it would be in converting those things into tangible property. Furthermore, you will be required to exercise some discernment in selecting what sort of tangible items will be valuable.
If electrical power becomes scarce, power tools become useless. Electronic devices become even more useless, barring those few which still serve some contextual survival purpose. Those will become even more precious if they have internal power for which there is some hope of recharging. Hand tools and weapons will always be valuable, with those devoted to the most common tasks becoming the most valuable. Anything human powered will be much more useful, including transportation. Conceptually, you would seek to identify things which allow maximum independence in their use. Example: bicycle tires which resist puncture, because you can’t afford to trust the system to keep the route free of debris which might poke holes. You have to consider independence in the global sense, and minimize our exposure to reliance on others. This improves your bargaining stance in dealing with a world suddenly become more hostile.