Retention
Ken Scott.
Your final point is the one that everyone always trots out when talk of FRIs comes up. The way I see it though is the jam today or jam tomorrow scenario. When most people leave (at roughly 38) they want to be finding a house if they don't already have one. The lump sum helps with this. The FRI temporarily replaces the lump sum and allows for said house purchase. I am well aware that there are past generations of guys that did very well on the housing market and now have their Goergian country estate with no mortgage before their sixtieth birthday, but there are those of us for whom that has not happened (due to the vagaries of the housing market and postings).
People should not always assume that just because an FRI wouldn't tempt them that it wouldn't tempt anyone. It would suit my circumstances very nicely and I am well aware of the whole airline seniority argument. I should also point out that circumstances change and two months from now I may change my mind and want to leave forthwith but I'm a fickle bugger. It's my prerogative.
BV