Macaulay Duration

I just came across a new formula in the CFAI mock exam, (1+r)/r. They say this is the formula for Macaulay Duration, but I don’t remember reading this anywhere. Can somebody explain this to me? Thanks.

(1 + r) / r is _ not _ a formula for Macaulay duration.

I came across it as well, Macaulay Duration = (1+r)/r. What is happening. I tried using the modified duration formula to arrive at the same outcome as the formula above, but to no avail… Pls help confirm the autenticity of this formula.

From Wiley “For fixed-rate coupon bonds trading at par or premium to par, longer times-to maturiet correspond to a higher Macauley duration. However, Macaulay duration for these bonds never rises above a threshold level defined by MacDur = (1+r)/r”

I have never seen that equation before and certainly will not be using to calculate Macauley duration

(1+r) / r is the duration of a consol, or perpetual bond.

yeup burberry got it on the spot: Page 531 in CFA material in the Fixed Income book…at the bottom

I see, Thanks!