好啊！

这个好！

1.a. Quantity equation gives us: M*V=P*Y, and based on the quantity theory of money, the velocity V is assumed fixed, thus we can get dM/M=dP/P + dY/Y. THE inflation rate is targeted at 2%, the growth rate of Y is 3%, so the proper monetary policy for the central bank is of a steady growth of money supply at the rate of 5% a year.
Use Fisher equation: i=π + r, i is the nominal interest rate and π is the inflation rate. Therefore, it is very straightfoward that real interest rate r=6-2=4% a year.
b. In a closed economy, no capital flow between countries, implying the equation S=I(r) holds. If a policy is adopted to encourage investment, real interest has to rise to equalibrate the loanable funds market. Given the target inflation rate is 2%, i=π+r, the nominal interest rises as well.

2. In a small open economy with perfect mobility of capital, real interest rate is fixed at the world level. Equation S-I=NX, since neither fiscal policy nor r has changed, NX is unchanged as well. Export declines due to foreign policy, and we know that net export is unchanged, so we must have the result of a fewer imports. Why imports fall? As a tighter policy is imposed on our exports, the demand for the products of our country decreases. Therefore, the price of products in our country is falling in terms of foreign products, ie. real exchange rate falls (depreciate).
So, net capital outflow=NX is unchanged, and real exchange rate decreases.

3.The economy in the situation of a is more likely to run a heavy trade deficit. Aagin, NX=S-I, and a large population of eldly require huge government expenditure that results less government saving. S falls and investment is unchanged with real interest rate fixed at the world level, as a consequence, NX=S-I declines and probably leads to trade deficit.

4. The central bank does not respond to this turmoil means LM curve does not shift. Households` pessimism reduces consumption, thereby shifting IS curve leftwards. The new IS curve intersects LM curve at a lower output level and a lower interest rate level.
The intuition: When demand falls, firms` inventory accumulates, so they reduce the production until the market equilibrum restored. In terms of money market, real money supply does not change, so a lower interest rate level is required to offset the negative effect of the less income on real money demand, leaving the money market in equilibrium.

谢谢，非常好