Opec crude production tumbled to a four-year low in February as “involuntary” production cuts from its more troubled members took their toll. A 280,000 b/d fall took the group’s average output down to just 30.76mn b/d for February, its lowest level since February 2015. The group has now cut far deeper than the 800,000 b/d it pledged in December as its share of global production shrinks further (MEES, 7 December 2018).

The 11 Opec members which signed up to the cuts –...