I'm attempting to write an article about the interaction between state retirement pensions and final salary schemes.

My recollection is that up to about the 1980's an employer had to either make substantial contributions to the State Earnings Related Pension Scheme (as did the employeed) or they could opt out if they could prove that their company scheme offered better terms than the state scheme (which in practice would probably mean that it had to be a final salary scheme. I think that this practice was ended by the then conservative government and that no such conditions exist.

I'm a bit surprised at what appears to be the lack of literature on the subject although I may be looking in the wrong places. Can anyone suggest any books or articles that give the history of this in any detail and also give what you earned, and also how I might get hold of them?

As a starter for 10 you might try The Law of Social Security by Ogus & Barendt, my recollection is that gives a potted history about individual benefits and will undoubtedly have a pile of references. And yet another sign that we are heading back to the 80's you might want to look at the Fowler Review (Green paper Cmnd 9517, White paper Cmnd 9578) to see their reasoning for what they did.