Economists normally splits goods into four categories:

• Public goods are non-excludable (so anyone can access them) and non-rival (I can use them as much as I want without limiting the amount you can use them). Broadcast television, national defense, and air are all public goods.
• Common-pool resources are non-excludable but rival (if I use them, you will have to make do with less). Iron ore, fish stocks, and grazing land are all common pool resources.
• Private goods are excludable (their access is controlled or limited by pricing or other methods) and rival. My clothes, computer, and the parking space I have in my lease but never use are all private goods.
• Club goods are excludable but (up to a certain point) non-rival. Think of the swimming pool in an apartment building, a large amusement park, or cellular service.

Club goods are perhaps the most interesting class of goods, because they blend properties of the three better understood classes. They aren’t open to all, but they are shared among many. They can be overwhelmed by congestion, but up until that point, it doesn’t really matter how many people are using them. Think of a gym; as long as there’s at least one free machine of every type, it’s no less convenient than your home.

Club goods offer cost savings over private goods, because you don’t have to buy something that mostly sits unused (again, think of gym equipment). People other than you can use it when it would otherwise sit around and those people can help you pay the cost. It’s for this reason that club goods represent an excellent opportunity for the right entrepreneur to turn a profit.

I currently divide tech start-ups into three classes. There are the Googles of the world, who use network effects or big data to sell advertising more effectively. There are companies like the one I work for that take advantage of modern technology to do things that were never possible before. And then there are those that are slowly and inexorably turning private goods into club goods.

I think this last group of companies (which include Netflix, Spotify, Uber, Lyft, and Airbnb) may be the ones that ultimately have the biggest impact on how we order our lives and what we buy. To better understand how these companies are driving this transformation, let’s go through them one by one, then talk about what it could all mean.

Netflix

When I was a child, my parents bought a video cassette player, then a DVD player, then a Blu-ray player. We owned a hundred or so video cassettes, mostly whatever movies my brother and I were obsessed with enough to want to own. Later, we found a video rental store we liked and mostly started renting movies. We never owned more than 30 DVDs and 20 Blu-rays.

Then I moved out. I have bought five DVDs since – they came as a set from Kickstarter. Anything else I wanted to watch, I got via Netflix. A few years later, the local video rental store closed down and my parents got an AppleTV and a Netflix of their own.

Buying a physical movie means buying a private good. Video rental stores can be accurately modeled as a type of club good, because even if the movie you want is already rented out, there’s probably one that you want to watch almost as much that is available. This is enough to make them approximately non-rival, while the fact that it isn’t free to rent a movie means that rented videos are definitely excludable.

Netflix represents the next evolution in this business model. As long as the Netflix engineers have done their job right, there’s no amount of watching movies I can do that will prevent you from watching movies. The service is almost truly non-rival.

Movie studios might not feel the effects of Netflix turning a large chunk of the market for movies into one focused on club goods; they’ll still get paid by Netflix. But the switch to Netflix must have been incredibly damaging for the physical media and player manufacturers. When everyone went from cassettes to DVDs or DVDs to Blu-rays, there was still a market for their wares. Now, that market is slowly and inexorably disappearing.

This isn’t just a consequence of technology. The club good business model offers such amazing cost savings that it drove a change in which technology was dominant. When you bought a movie, it would spend almost all of its life sitting on a shelf. Now Netflix acts as your agent, buying movies (or rather, their rights) and distributing such that they’re always being played and almost never sitting on the shelf.

Spotify

Spotify is very similar to Netflix. Previously, people bought physical cassettes (I’m just old enough that I remember making mix tapes from the radio). Then they switched to CDs. Then it was MP3s bought online (or, almost more likely, pirated online). But even pirating music is falling out of favour these days. Apple, Google, Amazon, and Spotify are all competing to offer unlimited music streaming to customers.

Music differs from movies in that it has a long tradition of being a public good – via broadcast radio. While that hasn’t changed yet (radio is still going strong), I do wonder how much longer the public option for music will exist, especially given the trend away from private cars that I think companies like Uber and Lyft are going to (pardon the pun) drive.

Uber and Lyft

I recently thought about buying a car. I was looking at the all-electric Kia Soul, which has a huge government rebate (for a little while yet) and financing terms that equate to negative real interest. Despite all these advantages, it turns out that when you sit down and run the numbers, it would still be cheaper for me to use Uber and Lyft to get everywhere.

We are starting to see the first, preliminary (and possible illusionary) evidence that Uber and Lyft are causing the public to change their preference away from owning cars.

A car you’ve bought is a private good, while Uber and Lyft are clearly club goods. Surge pricing means that there are basically always enough drivers for everyone who wants to go anywhere using the system.

When you buy a car, you’re signing up for it to sit around useless for almost all of its life. This is similar to what happens when you buy exercise equipment, which means the logic behind cars as a club good is just as compelling as the logic behind gyms. Previously, we hadn’t been able to share cars very efficiently because of technological limitations. Dispatching a taxi, especially to an area outside of a city centre, was always spotty, time consuming and confusing. Car-pooling to work was inconvenient.

As anyone who has used a modern ride-sharing app can tell you, inconvenient is no longer an apt descriptor.

There is a floor on how few cars we can get by on. To avoid congestion in a club good, you typically have to provision for peak load. Luckily, peak load (for anything that can sensibly be turned into a club good) always requires fewer resources than would be needed if everyone went out and bought the shared good themselves.

Even “just” substantially decreasing the absolute number of cars out there will be incredibly disruptive to the automotive sector if they don’t correctly predict the changing demand for their products.

It’s also true that increasing the average utilisation of cars could change how our cities look. Parking lots are necessary when cars are a private good, but are much less useful when they become club goods. It is my hope that malls built in the middle of giant parking moats look mighty silly in twenty years.

Airbnb

Airbnb is the most ambiguous example I have here. As originally conceived, it would have driven the exact same club good transformation as the other services listed. People who were on vacation or otherwise out of town would rent out their houses to strangers, increasing the utilisation of housing and reducing the need for dedicated hotels to be built.

Airbnb is sometimes used in this fashion. It’s also used to rent out extra rooms in an otherwise occupied house, which accomplishes almost the same thing.

But some amount of Airbnb usage is clearly taking place in houses or condos that otherwise would have been rental stock. When used in this way, it’s taking advantage of a regulatory grey zone to undercut hotel pricing. Insofar as this might result in a longer-term change towards regulations that are generally cheaper to comply with, this will be good for consumers, but it won’t really be transformational.

The great promise of club goods is that they might lead us to use less physical stuff overall, because where previously each person would buy one of a thing, now only enough units must be purchased to satisfy peak demand. If Airbnb is just shifting around where people are temporary residents, then it won’t be an example of the broader benefits of club goods (even if provides other benefits to its customers).

When Club Goods Eat The Economy

In every case (except potentially Airbnb) above, I’ve outlined how the switch from private goods to club goods is resulting in less consumption. For music and movies, it is unclear if this switch is what is providing the primary benefit. My intuition is that the club good model actually did change consumption patterns for physical copies of movies (because my impression is that few people ever did online video rentals via e.g. iTunes), whereas the MP3 revolution was what really shrunk the footprint of music media.

This switch in consumption patterns and corresponding decrease in the amount of consumption that is necessary to satisfy preferences is being primarily driven by a revolution in logistics and bandwidth. The price of club goods has always compared favourably with that of private goods. The only thing holding people back was inconvenience. Now programmers are steadily figuring out how to make that inconvenience disappear.

On the other hand, increased bandwidth has made it easier to turn any sort of digitizable media into a club good. There’s an old expression among programmers: never underestimate the bandwidth of a station wagon full of cassettes (or CDs, or DVDs, or whatever physical storage media one grew up with) hurtling down the highway. For a long time, the only way to get a 1GB movie to a customer without an appallingly long buffering period was to physically ship it (on a 56kbit/s connection, this movie would take one day and fifteen hours to download, while the aforementioned station wagon with 500 movies would take 118 weeks to download).

Change may start out slow, but I expect to see it accelerate quickly. My generation is the first to have had the internet from a very young age. The generation after us will be the first unable to remember a time before it. We trust apps like Uber and Airbnb much more than our parents, and our younger siblings trust them even more than us.

While it was only kids who trusted the internet, these new club good businesses couldn’t really affect overall economic trends. But as we come of age and start to make major economic decisions, like buying houses and cars, our natural tendency to turn towards the big tech companies and the club goods they peddle will have ripple effects on an economy that may not be prepared for it.

When that happens, there’s only one thing that is certain: there will be yet another deluge of newspaper columns talking about how millennials are destroying everything.