janeainsworth it is not a question of whether or not you are enrolled in a scheme, it is about what you do with the pension pot when you retire. Until now you had no option other than to buy an annuity, now you have lots of options. It is simply that the existence of all the other options means that fewer people will buy annuities and that will make the annuities this smaller group buy worth less.
Yes, annuity rates are based on an assessment of individual potential life expectancy but, currently, that is within a large group of annuants where the probability that the actual expectancy of the fund as a whole will mirror general population trends is high. Once the number of people within a fund falls, the probability that the members as a whole will mirror the general population closely is less sure, so in a large fund the smoker with a higher level annuity who lives to 100 is likely to be balanced by a hearty healthy person who falls under a bus three years after retiring, in a smaller fund there is a greater chance that the fund could have a profile skewed towards longevity - or indeed, truncated lives, but the first option is expensive and annuity rates have to protect the provider from going bust.