explain the answer in more details on question a to e
Consider a discrete-time v...
Jun 15, 2024
explain the answer in more details on question a to e
Solution
a
To solve for pt in terms of mt and Etpt+1, start with the given money demand equation:
mt−pt=c−b(Etpt+1−pt)
Rearrange to isolate pt:
mt−c=pt−b(Etpt+1−pt)mt−c=pt(1+b)−bEtpt+1pt(1+b)=mt−c+bEtpt+1pt=1+bmt−c+bEtpt+1
b
Using the law of iterated projections, express Etpt+1 in terms of Etmt+1 and Etpt+2:
Etpt+1=1+bEtmt+1−c+bEtpt+2
c
Iterate this process forward to express pt in terms of mt,Etmt+1,Etmt+2,…:
pt=1+bmt−c+1+bbEtpt+1
Substitute Etpt+1 iteratively:
pt=1+bmt−c+1+bb(1+bEtmt+1−c+1+bbEtpt+2)
Continue this process:
pt=i=0∑∞(1+bb)i1+bEtmt+i−c
Given the no-bubbles condition:
i→∞limEt[(1+bb)ipt+i]=0
Thus:
pt=i=0∑∞(1+bb)i1+bEtmt+i−c
d
Intuitively, an increase in Etmt+i for any i > 0 raises pt because higher expected future money supply increases the expected future price level, which in turn increases the current price level due to the forward-looking nature of price setting
e
Suppose expected money growth is constant, so Etmt+i=mt+gi. Solve for pt in terms of mt and g:
pt=i=0∑∞(1+bb)i1+bmt+gi−cpt=1+bmt−ci=0∑∞(1+bb)i+1+bgi=0∑∞i(1+bb)i
Using the geometric series sum formula:
i=0∑∞(1+bb)i=1−1+bb1=1+bi=0∑∞i(1+bb)i=(1−1+bb)21+bb=(1+b)2b
Thus:
pt=1+bmt−c(1+b)+1+bg(1+b)2bpt=mt−c+(1+b)2gb
An increase in g raises pt because it increases the expected future money supply, leading to higher current price levels
Answer
The final answers are as follows:
- pt=1+bmt−c+bEtpt+1
- Etpt+1=1+bEtmt+1−c+bEtpt+2
- pt=∑i=0∞(1+bb)i1+bEtmt+i−c
- An increase in Etmt+i for any i > 0 raises pt because it increases the expected future price level.
- pt=mt−c+(1+b)2gb, and an increase in g raises pt.
Key Concept
The relationship between money supply, expected future money supply, and price levels.
Explanation
The price level pt is influenced by the current money supply mt and the expected future money supply Etmt+i. An increase in expected future money supply raises the current price level due to the forward-looking nature of price setting.
explain in details the question a
Solution
a
To solve for pt in terms of mt and Etpt+1, we start with the given money demand equation:
mt−pt=c−b(Etpt+1−pt)
First, we rearrange the terms to collect pt on one side:
mt−pt=c−bEtpt+1+bpt
Next, we combine the pt terms:
mt−c=pt(1+b)−bEtpt+1
Solving for pt, we get:
pt(1+b)=mt−c+bEtpt+1
Finally, we isolate pt:
pt=(1+bb)Etpt+1+(1+b1)(mt−c)
Thus, the solution for pt in terms of mt and Etpt+1 is:
pt=(1+bb)Etpt+1+(1+b1)(mt−c)
Answer
The solution for pt in terms of mt and Etpt+1 is:
pt=(1+bb)Etpt+1+(1+b1)(mt−c)
Key Concept
Solving for the price level pt in terms of the money stock mt and the expected future price level Etpt+1.
Explanation
By rearranging the given money demand equation and isolating pt, we can express the current price level as a function of the current money stock and the expected future price level.