It is my contention that one of the benefits of a pension is that it provides a system for age-averaging.
Imagine three people, each born five years apart (say 1960, 1965 and 1970). These three people each invest the same amount of (inflation adjusted) money in the exact same way (e.g., 80% stocks/20% bonds in year #1). But because of the various market cycles, it is quite likely that the return after 30 years (and after that into retirement) will be different for each person, perhaps dramatically so.
The first question is whether there is any available analysis for this type of situation, I suspect there may be, but I couldn't find it.
Beyond that, are there sources of data which would allow me to do my own analysis? I think I would need historical inflation rates, stock returns and "bond" returns, each a month at a time.