@H_Bhardwaj margin requirements are the difference between value of a collateral and how much bank is offering.
eg: Normal time , margin requirement for gold , say be 20%. So if you pledge gold worth 100 Rs you will get only 80Rs from bank.
During Inflation, margin requirements are increased say 30%. So instead of 80 Rs you will get only 70 Rs from bank, so less money in your hand for circulation and thus combats inflation.
