The recent jump in government bond yields may or may not prove durable, but it prompts a wider question. Interest rates have been falling globally for 30 years. Sooner or later, they are going to start rising again. How might this affect business and investment behaviour?

That would depend on what caused it: a revival of inflation, say, or a shift in the balance between savings and investment. The latter is proposed in a paper from McKinsey, which argues that over the next two decades investment demand from China and other big emerging economies will outstrip global savings.

We need not dwell on the details of this, since it is not in the nature of 20-year economic scenarios to be strictly accurate. It serves rather as a handy framework for thinking through the consequences.