Post-Purchase Rationalization
🇳🇴Etterkjøps-rasjonaliseringDefinition
Post-purchase rationalization is the tendency to convince ourselves that a purchase – especially an expensive or impulsive one – was wiser than it actually was. Once the money is spent, the brain works to make the choice good.
Real-world example
The effect is well documented in consumer research going back to Festinger's classic dissonance studies in the 1950s. Cohen and Goldberg (1970) showed that car owners who had just bought a specific model spent significantly more time on advertising for *the car they already owned* than for competitors – actively seeking confirmation of a choice already made.
Apple users who've just switched from Android, and vice versa, show the same pattern: they suddenly discover their new platform has qualities they previously didn't weigh. Buyers of expensive weddings, homes, or MBA programs often tell stories that have grown prettier over time – not because they're lying, but because rationalization has replaced the original memory.
Supplementary perspective
Short- and long-term effects aren't the same. Right after a purchase, rationalization is useful – it protects you from ruining enjoyment of something you can't undo anyway. But over time it means you learn the wrong lessons from purchases: everything looks successful, so you make the same decisions again.
Practical advice
Recognize
- —Notice if you defend a recent purchase with arguments you didn't have before buying.
- —Check if you seek reviews mainly of the product you already own.
- —Watch when you minimize negatives that were clear before the purchase.
Counteract
- —Write down expected utility *before* buying, and revisit the note at 3 and 12 months.
- —Set a 'personal cooling-off period': 24 hours for impulse buys, a week for large ones.
- —Ask yourself honestly: would I buy this at today's price if I didn't already own it?
Ethical use
- —In procurement roles: document expectations, not just decisions.
- —As a seller: don't exploit that buyers will rationalize the purchase themselves – build real value instead.
- —In personal finance: distinguish 'that was lucky' from 'that was a good decision.'