Independent solution

How to solve this Interest Rate Valuation question

Setup

Setup

Separate growth in purchasing power from growth in the price level.

1+i=(1+i)(1+r)1+i=(1+i')(1+r)

Model

Model

The nominal accumulation factor is the product of the real and inflation factors.

1+i=1+i+r+ir1+i=1+i'+r+i'r

Compute

Compute

Expanding the product and subtracting one retains the interaction term.

i=i+r+iri=i'+r+i'r

Answer

Answer

The nominal rate is i prime plus r plus their product, corresponding to choice B.

i=i+r+ir(B)\boxed{i=i'+r+i'r\quad\text{(B)}}