Equity duration

An index has a forward dividend yield of 1.4% (assumption), and investors require $r=12\%$. (a) Under Gordon, find the implied $g$ and the modified duration. (b) The real rate rises 100 bp with $g$ unchanged. Compute the exact price change. (c) Instead, expected inflation rises 100 bp, raising $r$ by 100 bp, while firms pass through $\lambda=0.6$ of the inflation to $g$. Compute the exact price change. (d) Explain why measured equity "durations" are far below your answer to (a).