I think that in practice it will be a mean average. However, I will make that absolutely clear.
By withdrawing the facility to build a pension above the flat rate and modernising the system, removing elements such as savings credit and derived entitlement that no longer reflect the needs of the working-age population, we are able to fund the single-tier pension and improve the outcomes of groups such as the self-employed, carers and low earners, who have historically seen lower state pensions. It follows, therefore, that there are two means by which we could apply the new state pension to existing pensioners.
First, we could simply increase the pension of all existing pensioners to the full single-tier rate, if they are currently receiving less. In response to the question asked by my noble friend Lord Flight, we estimate that this would cost around £10 billion.