Many shades of black money - Hindustan Times
A lowdown on how India’s black economy deals thrive outside the financial system by creating a web of transactions that obscure the sources of slush funds.
What is black money?
Black money is income on which tax is evaded. It represents a large part of a bustling 

economy where transactions are carried out in cash circumventing banking channels.

What is the size of India’s black economy? 
Finance minister P Chidambaram is likely to reveal a new estimate of India’s unaccounted “black money”, most of it stashed abroad, in this year’s budget session and follow it up with a plan to hold it to account.