Payments - Or a Wink and a Nod!!

I like it.  But note how in your example it is the shopkeeper/merchant who assumes all the risk.  I mean, one month you may just leave and forget to pay, or you might actually die naturally aged over 100 of course and then who pays the merchant.

Most of the technological solutions to buying stuff have a lot of thought to where the risk is left, and how to minimise it.  Even in the Pay Now scenario, there is often a window of time where one payee can lose out (2-phase commit stops the online case). 

As for Pay Never - I guess you mean the barter system?  You run up some credit and sometime later you 'repay' with some other service to the value of the credit.  No money involved?  For example - perhaps you supply the shop with some goods which offsets your debt.  The operationalisation of this is  basically a stock market - where the value of different goods and services is continually traded and changing according to supply and demand.

@Advait R: Great post! I especially liked your KYC, face recognition and STP analogies. 

@John D:

You make a valid point around the role of technology in risk attribution / mitigation.

However, awareness of risk and how it is handled are highly dependent upon local business culture. Having spoken to many vendors of the type exemplified by Advait R - in the course of pushing retail payment technologies, I must add - I am fairly sure that they will have the following answers ready when the risk of default is pointed out to them: (1) If my customers delay payments, I will keep knocking on their doors so persistently that they will risk losing face with their neighbors and eventually cough up their payments (2) Very few people do such vanishing tricks; even if they do, there will be somebody else in the same house who I can grab to realize my payment (3) Children and grandchildren do most of the shopping for old people, very low chances of default due to natural death; in any case, my risk is limited to one month's shopping and it is bad karma to chase up for such a paltry amount from a dead person's relatives. While I may or may not agree with the form of risk management followed by the vendor, I have to accept it as a given. 

Besides, it's not as though payment technologies do such a great job of risk management. By focusing on eliminating risk of defaults, they introduce other - and arguably far greater - risks viz. potential loss of revenue from shopping cart abandonment, false positives, and so on. While some other technology does come along to solve these problems, we go back precisely to the crux of this post, namely, how the more things change, the more they remain the same. 

@ John D. POint well made about how payments technology tries to minimise risk or indeed appropriately assign it in the course of a transaction.

@ KS - I liked your reply about the difference between risk awareness and risk mitigation. As with my local vendor, I am sure his credit lines are not uniform and are based on an astute understanding of the client and her creditworthiness.