Nothing irritates specialist investors in emerging markets more than seeing all middle-income countries lumped into a single category: a special hatred is reserved for the “Brics” label slapped across the five wildly contrasting economies of Brazil, Russia, India, China and South Africa.

Yet despite manifest differences in economic structure and quality of policy making, emerging markets have suffered together this year from fears about rising interest rates and sliding commodity prices.

Given the disparate paths and policies among middle-income economies, it is implausible that the emerging market boom dating back to the early 2000s reflected only cheap borrowing and expensive commodities. But with a supportive external environment dissipating, even stable economies may find growth harder to achieve in the future.