to hold the value of the yuan down the Chinese central bank had to continually buy dollars and sell its own currency. To do so it printed yuan. In the normal course of things this would have unleashed domestic inflation, wiping out any competitive advantage and triggering social unrest. So, to “sterilize” the effects of its own intervention, the People’s Bank of China required all Chinese banks to hold large and growing precautionary reserves, effectively removing the currency from circulation.
