I spoke recently on “London’s place in the UK Economy” at a conference on Local Economic Growth: Recession, Resilience an d Recovery at St Catharine’s College, Cambridge. You can find my paper here. A full list of all papers can be found here.
My conclusions were: London specialises in globally competitive professional business services; it attracts businesses, in part, because of the agglomeration benefits they derive from being in London (close to similar and related businesses); this global competitiveness in service activities has led London to grow strongly over recent decades; London contributes more by way of taxation than it receives in public expenditure; and that investment in London benefits the rest of the UK.
Not all my conclusions were accepted by the other attendees (particularly the last point).