A: Tri-paradox, also known as triple dilemma, was put forward by American economist paul krugman on the basis of Mundell-Fleming model. It means that the independence of domestic monetary policy, the stability of exchange rate and the complete liquidity of capital cannot be achieved at the same time, but at most, two goals can be achieved at the same time and the other one can be abandoned. The independence of domestic monetary policy refers to the ability of a country to implement macro-stability policies for countercyclical adjustment, which mainly refers to whether a country has the ability to use monetary policy to influence its output and employment; Exchange rate stability refers to protecting the domestic exchange rate from speculative shocks and currency crises, thus maintaining exchange rate stability; The complete liquidity of capital does not restrict the free flow of short-term capital.