A big wage rise is prima facie a good thing for lower-paid workers, setting aside the job losses and cost-cutting that might result. But it swiftly becomes treated as an entitlement in our minds, which are more predisposed to dwell on (for example) lost paninis. And if workers think they are no longer being treated “fairly” — getting both the panini and the higher wages — they might take their foot off the pedal. That was argued by economist George Akerlof and his wife Janet Yellen — now US Federal Reserve chairman — in their “fair wage-effort hypothesis”, under which workers proportionately withdraw effort as their actual wage falls short of their fair wage.