BPP pg 348 Target - Dividend growth model of valuation

Annuity factors give the PV 'now' - time 0 - when the first flow is in 1 years time. If the first flow is in 4 years time, then it is starting 3 years late (time 4 instead of time 1) and therefore the PV is 3 years later (time 3 instead of time 0) and so needs discounting for 3 years.

You are welcome :-)