There are some anecdotes just so good that almost every story about a particular economic principle begins the same. So too this article begins with cake mix. In the 1950, the story goes, US food company General Mills wanted ideas on how to sell more of its Betty Crocker brand of instant cake mixes. It put psychologist Ernest Dichter – the "father of motivational research" – on the case. Dichter ran focus groups. Change the recipe, he then advised the company. Replace powdered eggs in the cake mix with the requirement to add fresh eggs. All-instant cake mix makes baking too easy. It undervalues the labour and skill of the cake maker. Give the baker more ownership in the final result. And the rest is history.

Almost seven decades later, the idea of making things more laborious to get consumers to value them more is an established marketing tactic. We now know it as the "IKEA effect".