Diderot effect

The Diderot effect is a pattern in which acquiring a new possession prompts further purchases to make belongings feel coherent, creating a cycle of consumption.

Connect

Endowment effect: A bias in which people value an object more once they own it. New possessions can reset what feels worth keeping, replacing, or adding.
Denis Diderot: An eighteenth-century French philosopher, writer, and editor of the Encyclopédie. His essay about a new robe supplied the effect's name and central story.
Lifestyle inflation: The tendency for spending to rise as income increases, reducing the gains from higher earnings. Both patterns turn an initial change into pressure for additional consumption.
Consumer debt: Debt incurred by individuals for personal or household consumption rather than business investment. A chain of coherence-seeking purchases can exceed available income.
Mental accounting: The tendency to sort money into separate mental categories rather than treating it as fully interchangeable. Separate spending categories can make related purchases feel justified or distinct.
Regrets on Parting with My Old Dressing Gown: An essay by Denis Diderot about replacing a dressing gown and the purchases that followed. Diderot describes how one elegant robe made his other possessions seem shabby.
Interior design: The planning and arrangement of interior spaces to support their use and appearance. A new furnishing can make mismatched rooms seem to call for further purchases.
Overconsumption: The use of goods and resources beyond what is needed or sustainable. The effect is one pathway by which consumption can expand beyond practical needs.
Social comparison theory: A theory that people evaluate themselves by comparing their abilities and opinions with those of others. Comparisons can shape which possessions seem appropriate for a newly acquired item.
Encyclopédie: An influential French reference work edited by Denis Diderot and Jean le Rond d'Alembert in the eighteenth century. Diderot's account emerged from the same intellectual world as his editorial work.