After the Indian government withdrew most of the Indian currency notes from circulation last night, there has been a fear that this would be so disruptive that the economy would just go off the cliff. I think this fear is totally misplaced. Contrary to what some economists might tell us, money does not make the world go round. We finance people know that the world actually runs on credit. Economists tend to think that credit is what you use when you run out of money. Nothing could be further from the truth. In reality, money is what you use when your credit has run out. I work for my employer on credit, my newspaper vendor sells me newspaper on credit, companies buy raw material on credit and sell their products on credit. If you find somebody having difficulty doing any of these transactions on credit, you can be sure that that somebody is a whisker away from bankruptcy.
Yes, today you will not be able to go to your neighbourhood grocery store and buy anything with the 500 rupee note in your wallet. But if you cannot buy whatever you like on credit from the same neighbourhood grocery store, then you have a very serious problem on your hand; a problem that will not go away when the banks reopen tomorrow. If you really find yourself in that position, you should be very worried and you should drop everything that you are doing, and work slowly and painstakingly on rebuilding your credit. For in a capitalist society, if you have lost your credit, you have lost everything.
So, yes, the Indian economy will be fine even though it is denuded of most of its currency for the next few days. Apart from the few people who are travelling (other than your credit card, you have no credit amidst strangers), it will not even be too inconvenient for the vast majority of people. I have no first hand knowledge of the black economy and would be reluctant to comment on that, but I suspect that this too runs more on credit than on cash. It might be premature to conclude that the economy would suffer from a fall in demand due to disruption of the black economy.
If you want historical evidence on how the world copes with disruptions to money supply, I would recommend an excellent article early this year by the Bank of England on how Ireland coped with a six month long bank strike in the 1970s. Or you could look at the experience from 19th century US in the wake of frequent bank failures and how cities and towns rebuilt their economy on alternative credit networks. Or you could read Niklas Blanchard on complementary currencies.