Membership of the European Union has contributed to the economic prosperity of the United Kingdom. Uncertainty about the outcome of the referendum has already started to weaken growth in the United Kingdom. A UK exit (Brexit) would be a major negative shock to the UK economy, with economic fallout in the rest of the OECD, particularly other European countries.

Household incomes are around £1,500 year lower today than they were expected to be before the Brexit referendum – with the UK having experienced the sharpest income growth slowdown of any economy for which the OECD publish data.