The Blockchain
Why does the blockchain capture the imagination of so many people that really understand it? The blockchain is an intellectual construct that is laid on top of the societal layer to increase its robustness. It takes time, the economy of the intellect, and applies it to the economy of society.
Resource based economies are generally time agnostic. Our human-societal brains(System I) will even trick us into taking a smaller sum of cash now than at a point in the future even when the return in the future is ridiculously high. It isn't until the return is so large that our human-intellectual brains(system II) trip and make us say...wait a second....I'll wait.
The fact that we accept money as a form of payment is a bit of miracle. We figured out intellectually that a stand in for our sheep and wheat would be advantageous. This timeshifting of resources helps us, but it is subject to a number of bad actions that breaks the trust. In fact we hear often that money is only as good as the trust people put in it. This is true! It is just paper(or bits in a machine). The blockchain takes this to a logical end point by codifying money across time. The problem with money still remains that as market conditions change, the value of money can drastically change.
If we want there to be 'enough' money out in the world, there should always be enough to buy all the goods that are being produced. Of course things can change very quickly and things like a war could greatly reduce the amount of output that an economy can generate. It is extremely difficult to control the money supply when this happens and it typically leads to some form of instability. But with the blockchain, all transactions can be filtered through a set of intermediaries. If the economy collectively decides that a 1/3 reduction in money supply is necessary, via a blockchain, it can be enforced on the next transaction of each account in the system by the underlying algorithm or by a hard fork. I am not suggesting we do anything as drastic as this because it could decrease the predictability of markets and, if markets like anything, it is predictability.
The blockchain acts as a sort of time machine for our resources. We can walk backwards in time and make decisions based on where money has been and we can put future restrictions on cash via smart contracts. Future proofing anything is tough and so our smart contracts need to really be smart and offer us a means of flexibility. This is going to be an important field of study: figuring out how to maintain flexibility without having a system that can be gamed.
I think the final system will need to be subject to rule of law and open to the fundamental principles of common law. Common law dictates that we a subject to customs and judicial precedent. The whole sum of custom and the body of judicial precedents are hard things to code into a smart contract, and even harder if your smart contract system is limited in the amount of processing power it can employ.