The problem you don't get the returns once you start taking the pension. The returns help the fund to grow and help to guarantee your pension. The pension usually comes in the form of an annuity, and is not indexed and does not provide you an annual increase. It is the same payment. Ask anyone or Google  about defined pension plans, the most common word used is gold plated. The money never runs out , you can pass on up to 60% to your spouse and is indexed to inflation. Full disclosure I have one, and my take home has grown by over thirty per cent since I retired. My amount will nevr go down only up. It would be embarrassing to put down on paper what I've taken in so far. There is no other pension that comes remotely close.