Last week, trading began in Nigeria’s Guaranty Trust Bank global depositary receipts on the London Stock Exchange. The debut not only points to the extent of financial reform in Lagos, but also to big progress by sub-Saharan economies. Investors should take note.

The commodity price boom has combined with wide-scale debt forgiveness to boost sub-Saharan economies. Excluding South Africa, annual growth has averaged 7 per cent for the past five years, the fastest sustained pace in at least 50 years.