Yes, the issue is that when they were introduced you had government bond yields of well over 10%. Equities were expected to return even more. Pension promises

Yes, the issue is that when they were introduced you had government bond yields of well over 10%. Equities were expected to return even more. Pension promises seemed like a cheap benefit to offer, and one that was mutually beneficial. Couple this with mortality rates falling (expected lifetime increasing) and you have a bunc of completely unaffordable promises. There is a very very good reason that final (and even career average) salary schemes are being phased out. Companies have finally discovered just how expensive their promises are, and they are closing schemes as fast as they can get away with it. The government, meanwhile, buries it's head in the sand because the taxpayer cannot go insolvent. And even small changes to pension terms result in strikes. The mathematics is pretty trivial for this rough estimate, but 30% of salary is low ballpark of the contributions required to meet obligations with a 95% probability over 40 years. Admittedly I'm using an internal asset model which is relatively prudent, with long term derisking, and merely using todays retirement age, and mortality tables. It's probably a lot worse than that (but could be better, I mean this recession malarky can't go on forever right?).