The Chair Theorem: Why Our Homes Are Full of Things That Are Worth Almost Nothing

We live surrounded by hundreds, sometimes thousands, of objects. Yet we continue to manufacture, buy and resell more of them every day. How can a society that is already so well equipped absorb this enormous quantity of goods? And why do some perfectly usable objects end up being worth almost nothing?

It all starts with a simple chair

Anyone can try the experiment. Imagine opening Facebook Marketplace, searching for “chair” and looking within a few miles or kilometres of your home. Return to the search regularly and watch the new listings appear. In France, the same experiment can be carried out on Leboncoin, a local classifieds platform where a saved-search alert provided the starting point for this reflection.

Day after day, more chairs appear. Old chairs, modern chairs, industrial chairs, wooden chairs and plastic chairs, offered individually or in sets. Some cost several hundred euros. Others cost a few dozen. Some are even being given away. And this search covers just one type of object within a limited geographical area.

To grasp the scale of the phenomenon, imagine that 500 new listings appear every day within a particular area. That would mean 3,500 listings in a week and 15,000 in a 30-day month. These figures are an illustrative assumption, not the result of a survey of Facebook Marketplace or Leboncoin.

But they allow us to ask a surprising question: who could possibly buy all these chairs? A chair is not a consumable product. Once purchased, it can remain useful for ten, twenty or fifty years. There is no need to buy a new one every week.

So how do we explain this constant flow of objects looking for new owners? And, above all, what happens to those that find nobody? This is the starting point for what, with a little scientific licence, we will call the chair theorem.

First observation: we own far more objects than we realise

Take an ordinary 40 m² apartment, roughly 430 square feet. At first glance, its contents seem fairly simple: a bed, a table, a few chairs, a wardrobe, a sofa and some household appliances. But try counting the objects that are actually inside it.

In the kitchen: plates, glasses, cutlery, saucepans, utensils, small appliances, containers and accessories. In the cupboards: clothes, shoes, bags, household linen and objects kept for no particular purpose. On the shelves: books, documents, photographs and keepsakes. Add tools, cleaning products, electronic devices, lamps, picture frames and the countless small objects of everyday life.

The total can quickly reach several hundred or even several thousand objects, depending on how we count them. Yet there is nothing exceptional about this apartment. Now multiply its contents by the homes in a building, then a neighbourhood, then an entire city. The resulting quantity of objects is difficult to imagine.

Our society is not short of objects. It already owns an enormous quantity of them. And that is precisely what makes the chair experiment interesting. A single chair seems unremarkable. Thousands of chairs offered for sale within a limited area reveal a much broader economic reality.

Second observation: objects often outlast our need for them

A piece of furniture is not necessarily replaced because it is worn out. It may simply no longer meet its owner's needs. A couple moves into a smaller home. A family changes its décor. An inherited apartment is sold. A child leaves the family home.

In each of these situations, objects that are still perfectly usable become available. Their physical lifespan can be much longer than the period during which their owners want to keep them.

This is particularly striking with some older furniture. Imagine a beautiful nineteenth-century wardrobe. It was made from quality wood, with precise joints and real craftsmanship. Creating it required time, materials and considerable technical skill. More than a century later, it may still be perfectly functional. Yet it can be difficult to sell.

Not because it is poorly made, but because tastes have changed, homes may be smaller and buyers have countless alternatives. A craftsperson might have spent several days making a piece intended to last for generations. A hundred years later, a buyer may need only a few seconds to decide that it does not suit their décor.

The second-hand market is not a cabinetmaking competition. The quality of the craftsmanship does not guarantee market value. Of course, some antiques, signed pieces and designer furniture retain considerable value. But age and quality alone are not enough to create demand.

Third observation: objects keep arriving on an already crowded market

Let us return to our local chair listings. Each new advert represents one object, or sometimes several, looking for a new owner. But chairs are only one category among thousands. We also need to consider tables, sideboards, wardrobes, sofas, lamps, books, clothes and household appliances.

And classified adverts represent only part of the movement of objects. Some are given to friends and relatives, passed on to heirs, collected by charities, sold at flea markets or taken away for disposal. Meanwhile, the production of new goods continues.

Two movements are therefore taking place at the same time. On one side, homes gradually release some of the objects they contain. On the other, new objects continually enter those same homes. The second-hand market tries to organise part of this circulation.

But there is a fundamental difference between offering an object for sale and actually finding a buyer. A published advert is not a completed sale. And an advert disappearing does not necessarily mean that the object has been sold. It may have been deleted, reposted or abandoned.

This is why the number of new listings cannot, by itself, measure market saturation. It does, however, reveal the scale of the activity. The question is not simply how many objects are being offered for sale, but how many can actually find a new home.

Fourth observation: abundance changes what objects are worth

Now imagine a wooden chair bought for €120. It is sturdy, comfortable and still in good condition. Its owner wants to sell it and lists it for €60. No buyer. The price drops to €40, then €25. Eventually, the owner accepts €15. The chair has lost 87.5% of its purchase price.

Yet it still has all four legs, its backrest and its seat. It performs exactly the same function. What has happened? Much of the answer lies in abundance. A potential buyer may have dozens of comparable chairs to choose from nearby. They can pick another model, negotiate, wait for a better opportunity or buy new.

The owner, meanwhile, often thinks in terms of the price originally paid and the quality of the furniture. But the market does not automatically reward either of those things. An object is not necessarily worth what it cost to buy, or what it cost to make. It is worth what a buyer is willing to pay for it.

This distinction helps explain why beautiful furniture can sometimes sell for very little. It also explains why ordinary objects, produced in very large quantities, can quickly lose a substantial share of their market value. And it brings us back to the central idea of our theorem: the problem is not the chair. It is that chairs are everywhere.

Fifth observation: even free furniture can cost too much

Let us take the reasoning to its most surprising paradox. Imagine a large solid-wood wardrobe. It is in good condition, works perfectly and its owner decides to give it away. The asking price is therefore zero euros. Yet nobody comes to collect it.

Why? Because the wardrobe is on the fifth floor above ground level in a Parisian building with no lift. Collecting it may mean taking it apart, finding a vehicle, bringing several people, arranging parking and carrying all the pieces. The furniture is free. But collecting it can cost time and money.

A potential buyer may then prefer a new piece that is smaller or delivered to their home. Here is another contradiction: an object can have positive value in use while still creating an economic burden for the person who wants to collect it.

And that burden can affect its owner too. If nobody will come for the wardrobe, the owner may have to arrange its removal. The object that once represented a substantial purchase then becomes an expense. It has lost none of its usefulness. What has changed is the cost of keeping it and moving it on.

Sixth observation: time can erode the remaining value

Imagine two owners with exactly the same wardrobe. The first simply wants to change their décor and has six months to find a buyer. The second must leave their apartment in three days. The furniture is identical. But the owners do not have the same amount of time.

The first can wait for a satisfactory offer. The second needs a quick solution. They may accept a lower price, give the furniture away or pay to have it removed. The value an owner can actually obtain therefore also depends on how much time they have.

This is particularly important when moving home or dealing with an inheritance. A family may hope to sell several pieces of furniture separately. But photographing the objects, publishing adverts, answering messages and arranging collections all take time. When a property needs to be emptied quickly, these tasks can become difficult to fit around the circumstances.

And if housing or storage costs continue to accumulate, waiting for a better price can sometimes cost more than the expected proceeds. The highest theoretical price does not always produce the best financial outcome.

What should we do with all these objects?

The chair theorem does not mean that old furniture or second-hand objects are worthless. It simply invites us to distinguish between different situations. Some objects have genuine market value and deserve an appraisal. Others are perfectly usable but can only be sold for modest amounts. Some will find a second life more easily through donation or reuse. Finally, others will need a suitable removal and waste-treatment solution.

This distinction matters particularly when an apartment or house needs to be cleared. A property full of furniture does not necessarily contain a valuable collection of possessions. Conversely, a small object forgotten in a cupboard can sometimes have more resale potential than an entire dining-room suite.

During a professional clearance, items with resale value can sometimes be recovered and their value offset against the overall cost of the work. But that value must be assessed in light of actual demand, transport constraints and the costs involved in putting the objects back into circulation.

Conclusion: the paradox of a society that already owns almost everything

The chair theorem begins with a very simple experiment: watching new chair listings appear within a particular geographical area. But this experiment opens up a much broader line of thought.

We live in a society whose homes already contain enormous quantities of objects. Those objects can remain usable for decades, even as our needs, tastes and ways of life change. Every day, some of these existing possessions seek a new destination, while new goods continue to be made and bought.

The resulting abundance helps explain why perfectly functional objects can lose almost all their market value. And why some can even end up costing money to the people who want to part with them.

The next time you see a chair advertised for €10 on Facebook Marketplace or another local classifieds site, ask yourself: how many chairs are already around us, and how many people actually need to buy another one? Perhaps that is where the real chair theorem begins.

Do you need to clear an apartment or house?

When moving home, dealing with an inheritance or preparing a property for sale, it is not always easy to distinguish between objects that can be sold, those that can be donated and those that will cost money to remove.

Mastoc Débarras clears homes, cellars and business premises in Paris and the wider Île-de-France region. To help us prepare an estimate, you can send photographs of the furniture and the rooms to be cleared, along with the location, floor, whether there is a lift and your preferred timeframe.

This information helps us assess the volume, access requirements and any opportunities to recover value from the objects. Contact Mastoc Débarras to request a quote tailored to your situation.