A year and nine months after demonetisation, has the move to crack down on black money proved to be a failure? Economist Surjit Bhalla, a member of the Prime Minister's Economic Advisory Council, disagrees. Speaking exclusively to NDTV, Mr Bhalla said one of the biggest objectives of demonetisation was formalisation of the economy, and the big jump in tax revenue implies that demonetisation was a huge success. On Reality Check, we take a look at what the government claimed then and what we know now and ask the question, did India really need demonetisation?