1) Black money refers to funds earned through illegal or underground economic activities that are untaxed. India generates the most black money globally at $1,456 billion. 2) Major sources of black money include gambling, drug trafficking, money laundering through hawala networks and Swiss banks. Several scams like 2G, Commonwealth Games, Satyam, and IPL have also generated huge amounts of black money. 3) Measures needed to reduce black money include amnesty schemes, simplifying tax laws, increasing transparency, international cooperation, and educating people about the harms of corruption and black money. Bringing black money back could help repay foreign debt and boost the economy.