Key takeaways
- In every one of these chains the first purchase was reasonable. The cost came from the things bought afterward to match it.
- In our illustrations the follow-on purchases range from a little under the price of the first item to more than four times it, and the house chain runs to five figures.
- Almost every chain had a clear stopping point right after the first purchase, before anything that still worked was replaced to match.
Diderot’s own chain ran from a dressing gown to a desk, a clock, a mirror and a wall of paintings. Two and a half centuries later the objects have changed and the mechanism has not. Here are ten modern chains, told as short stories. Every dollar figure is an illustration, a round number for a typical US purchase, not data. What matters is the shape: one reasonable purchase, then a run of others made to match it.
1. The couch that redecorated the living room
Maya’s old sofa sagged, so she bought a good one in deep green velvet for $1,400. It looked wonderful and made everything near it look tired. The beige rug went first, then the scratched coffee table, then the lamp she had owned since college.
The chain (illustration): rug $350, coffee table $400, side table and lamp $250, cushions and a throw $120, curtains $180, a media console $500. Follow-ons: about $1,800, more than the sofa itself.
Where it could have stopped: at a sofa chosen to suit the room she already had.
2. The first “real” job and the professional wardrobe
Daniel started an office job and bought two pairs of trousers and a blazer for $450. Then his sneakers looked wrong with the trousers, his backpack looked wrong with the blazer, and by spring his weekend clothes looked like a student’s.
The chain (illustration): leather shoes $150, a work bag $200, a watch $250, a weekend wardrobe refresh $400. Follow-ons: about $1,000.
Where it could have stopped: at a small, fixed set of work clothes worn on repeat, the idea behind uniform dressing.
3. The phone that needed everything else
A $1,000 phone arrived without a headphone jack and without a charger in the box. That was the start.
The chain (illustration): case and screen protector $60, wireless earbuds $250, a fast charger and cables $70, a smartwatch that pairs with it $400, more cloud storage at $3 a month. Follow-ons: about $820 in the first year, and the storage keeps billing.
Where it could have stopped: at the case. The old earbuds worked with a $10 adapter.
4. The standing desk
Priya bought a $600 standing desk to work better from home. At its new height her old chair looked flimsy, and the laptop sat too low.
The chain (illustration): an ergonomic chair $500, a monitor arm $120, a second monitor $250, a standing mat $60, cable trays and a desk lamp $90. Follow-ons: about $1,020.
Where it could have stopped: after two weeks of using the desk with a stack of books under the laptop, to learn what was really missing.
5. The espresso machine
A $700 machine was meant to replace a daily café habit. Then the online guides explained that pre-ground coffee would never do.
The chain (illustration): a burr grinder $300, a scale, tamper, knock box and milk jug $120, new cups $60, canisters $80, and specialty beans at about $520 a year instead of $150. Follow-ons: about $930 in the first year.
Where it could have stopped: at the machine and ordinary beans, judged against the café bill rather than against a hobbyist’s setup.
6. The road bike
Sam bought a $1,800 road bike to get fit. The group he joined had clipless pedals, matching kit and computers on their handlebars.
The chain (illustration): pedals and shoes $250, jerseys and shorts $300, a lighter helmet $200, a bike computer $350, an indoor trainer $600, a car rack $400. Follow-ons: about $2,100, more than the bike.
Where it could have stopped: at pedals and one set of kit, with the rest put off until a season of riding proved the habit.
7. The baby’s nursery
A crib was a real need. The $400 crib came from a furniture line that also made a matching dresser and a glider, and the room was repainted to suit them.
The chain (illustration): matching dresser and changing top $500, glider chair $600, paint $150, curtains, rug and lighting $300, wall art $200. Follow-ons: about $1,750.
Where it could have stopped: at the crib, a secondhand dresser and a changing pad. A baby is a good reason to change a room; a catalog photo is not.
8. The engagement ring and the wedding
A $5,500 ring set a standard. A plan for a small $8,000 wedding started to look modest beside it.
The chain (illustration): a dress that suits the ring in photographs, $1,800 instead of $600; a photographer good enough for both, $3,500 instead of $1,500; a venue that suits the photographs, $9,000 instead of $3,000; flowers to match, $2,000 instead of $500. Follow-ons: about $10,700 above the original plan.
Where it could have stopped: at a wedding budget set before the ring was bought, and held to.
9. The gaming PC
Leo bought an $800 graphics card. The power supply could not run it, and the old processor held it back.
The chain (illustration): power supply $150, processor, motherboard and memory $700, a new case $150, a high-refresh monitor $400, keyboard, mouse and headset $300, a gaming chair $350. Follow-ons: about $2,050, two and a half times the card.
Where it could have stopped: at a card matched to the machine he had.
10. The new house
A bigger house in a nicer neighborhood is the Diderot effect at full size. The old furniture filled two rooms of a four-room house and looked small in all of them.
The chain (illustration): dining set $1,500, guest bedroom $1,200, rugs and window coverings $3,000, patio furniture $1,500, lawn and garden tools $800, a second sofa $1,800, and a car that looks at home in the driveway, $4,000 more than the old one was worth. Follow-ons: about $13,800 in the first year, before the higher bills.
Where it could have stopped: at furnishing one room at a time, and only the rooms in daily use. The economist Robert Frank and his coauthors argue that what counts as an adequate house is set by the houses around it, which is one reason a move into a richer area pulls so hard.
What the ten have in common
Nobody in these stories bought anything foolish. Each first purchase answered a real want, and each follow-on was small next to the one before. The chains grew because every new item was judged against the last one rather than against the plan, and because the old things, nearly all of them still working, now looked wrong. Diderot noticed the same thing in his own study.
Before your next big purchase, write out the chain it might start and price it, or let our Chain Cost Calculator do the sums. Then read seven rules that stop the chain, and give the second purchase thirty days before you make it. The hub page explains why the pull is so strong.
Questions readers ask
Are these dollar figures real data?
No. They are round illustrations of what each link might cost a US shopper, chosen to show the shape of a chain, not survey results or price quotes. Your own chain could cost far less or far more. What carries over is the pattern, where each purchase is judged against the last one rather than against the original plan.
Is every follow-on purchase part of a Diderot chain?
No. Some purchases really do depend on each other. A new camera body may need a lens, and a new printer needs ink. The Diderot test is simpler. Did the old thing stop working, or did it only stop matching? Replacing something that still does its job, because it now looks wrong beside something new, is the effect at work.
Which kinds of purchases set off the longest chains?
Anything that lives in a set that people see together. A room is judged as one picture, so furniture chains run long. Clothes are judged as an outfit, and gear for a hobby is judged as a kit. A single object used on its own, such as a kitchen knife, rarely starts much of a chain.
How can I estimate my own chain before I buy?
List everything the new item will sit next to, mark the things that will look worse beside it, and price a replacement for each. Add the total to the price of the first item. Our Chain Cost Calculator does the adding and shows the result in months of saving.
Sources
- Culture and Consumption: New Approaches to the Symbolic Character of Consumer Goods and Activities (Grant McCracken, Indiana University Press, 1988; this page is the 1990 paperback) Chapter 8, "Diderot Unities and the Diderot Effect," the source of the idea that goods are judged as consistent sets.
- Bellezza, Ackerman and Gino (2017), Be careless with that: Availability of product upgrades increases cavalier behavior toward possessions, Journal of Marketing Research 54(5) Studies, including data on lost phones, showing that people take less care of what they own when an appealing upgrade is available.
- Frank, Levine and Dijk (2014), Expenditure cascades, Review of Behavioral Economics 1(1-2) How the spending around us sets the standard for what counts as adequate, from interview suits to the size of a house.
- Regrets sur ma vieille robe de chambre (Denis Diderot, Œuvres complètes, Garnier, 1875, volume IV) The original chain, a scarlet dressing gown and a refurnished study.
Page history: first published .