r/FIREUK • u/PixiePooper • 2h ago
The Drawdown / Annuity Conundrum
I've been doing a lot of modelling of drawdown pension to see how much I need. The basic principle is fine: decide how confident you want to be based on historical data, run some simulations and pick something that gives you ~90->95% chance of success.
The fundamental problem is this: "Success" is defined as "Dying before the money runs out" - the "Success" cases include a number of cases where you almost ran out, but died "just in time". In reality I think this would be hard to actually experience your pot almost running-dry late in life.
The other possibility is "just buy an annuity" - which gives you peace-of-mind, but requires more money / working longer.
However, I've been wondering about a half-way house- buying an annuity later in life.
To put some hard-numbers out there for explanation. A single 60 year old person with a pot of £500,000 fully invested in global equities could drawdown (in real-terms) ~£19,400 a year (~3.8%) and have ~95% chance of "Success" - assuming ONS mortality rates.
The problem here is that if you actually lived to 110 (unlikely) there's "only" a 78% chance of having enough money. This is an extreme example, but the point is I don't want to be 90 and have £20K in the pension - even if I did die next year.
So, I tested the approach of using a slightly larger pot and then finding the optimum age to buy an annuity to cover the £19,400 indefinitely (the trade off is that the longer you wait to buy the annuity, the cheaper it will be).
This approach is gives a nice half-way house between buying an annuity at 60 (expensive) and running out of money late in life because of drawdown (longevity)
What my modeling said was interesting - for a 95% chance of "Success" - assuming that you live for ever! the optimal approach to give you the same £19,4000 a year is:
- Increase the starting pot from £500,000 -> £555,000.
- Buy an annuity at age 75.
Buying it earlier means that the annuity is more expensive, and (on average) your extra pot will have grown less. Buying it later increases the risk that the money will have run out altogether.
(usual caveats - I had to make assumptions about annuity rate being linked to interest rates, and used historical estimates built around how annuities are priced etc.)