I've been looking at ONS data on gross disposable income today from https://www.ons.gov.uk/economy/regionalaccounts/grossdisposablehouseholdincome/bulletins/regionalgrossdisposablehouseholdincomegdhi/1997to2020. In all regions disposable income has been growing but the per head disposable income in London is both larger than all other regions (not surprising) and has been growing in comparison to them over the past 25 years (not surprising). For instance, in 1997, Yorkshire and the Humber had 74% of London's disposable income per head. By 2020 it was 61% of London. As a country we've been concentrating wealth.