The fourth quarter surge in oil prices means Opec can head into the new year buoyed by the knowledge that it is guaranteed an attractive year-on-year revenue rise. Furthermore, the good cheer looks set to carry into 2018. MEES estimates the group’s revenues ought to rise nearly 30% this year to more than $575bn, and a further 11% to nearly $650bn in 2018 (see table).

This is based on an assumption that Opec members maintain broadly stable levels of compliance with the production...