Around the world, people are wondering nervously what automation might mean for their jobs. In Britain, it may have a striking, distinctively local twist. It won’t just eliminate some jobs and create others—it also risks heavily exacerbating the country’s north-south divide.

That’s one of the key findings from the blockbuster Cities Overview 2018 report, released Monday by the British urban think tank Centre for Cities. According to the report, the gulf between the largely ex-industrial cities of…