Do city people really like to share more? Emily Badger of The Atlantic Cities suggests a new and fascinating phenomenon in urban areas — that city dwellers are moving toward a culture of shared ownership of everything from cars to power tools.

Badger shares this thought in an essay from the new TED Book City 2.0: The Habitat of the Future and How to Get There, an anthology that suggests bold ideas for how we can create thriving cities. Born out of The City 2.0 TED Prize and produced in partnership with The Atlantic Cities, the book features essays from 12 authors, tackling topics ranging from transportation to food to public art.

Yesterday, we heard from City 2.0 essayist Diana Lind on why cities should be highway-free. Today, we asked Emily Badger to tell us more about her vision of sharing within big cities.

In your essay, you suggest that a culture of sharing has arisen in cities because of limitations of physical space. What’s created this culture?

All over the world, the populations of cities are swelling. This is the acceleration of a long-running transition as societies everywhere become less rural and more urban. So the question then becomes: Where do we put all of these people? And how will they live together? Ideally, we need cities to grow in population without expanding at an equal rate in geographic size. We need urbanization without sprawl. And so this means we need to try to accommodate more people within the footprint of existing cities. That means more people living in apartments instead of detached homes. That means using a car-share instead of individually owning cars. That means using public parks instead of private backyards — all simply because there just won’t be enough space in crowded cities for everyone to individually own all of these things.

Is there also an economic reality causing all this sharing?

A lot of people learned during the recession that it was financially unsustainable to have a 4,000-square-foot house and two or three cars. The “sharing economy” sounds like a nice idea for altruistic people willing to give rides in their cars to strangers. But sharing is also fundamentally a way for people to cover car payments or monthly rent bills. I suspect there are a lot of people on Airbnb who wouldn’t be able to afford their homes if they couldn’t make some money each month renting out a spare bedroom.

Sharing isn’t a new idea. Tell us a little about the history of urban sharing and how we drifted away from it.

We have always shared a lot of things, especially in cities. We share books at the library. We share transportation in a subway car. We share washing machines at a laundromat. Cities in many ways are historically a kind of shared commons. But, particularly in the U.S., we started to move away from that mentality after World War II — and a lot of the rest of the world, especially the developing world, has followed our lead. A lot of people moved out of cities for a more spacious, suburban lifestyle that simply didn’t require us to share assets in the same way. Culturally, we came to prize large private homes over apartments, multiple cars over public transit, and personal appliances over laundries. Now that demographic trends are shifting back into cities, though, this story is starting to change.

What are some of the downsides of sharing?

I don’t want to sound like sharing is awesome in every way! Obviously, we give up some comfort and convenience when we don’t individually own things, and there’s a tradeoff there. I live in an apartment, and sometimes I have to listen to my neighbors through our shared walls and ceilings. If you do Zipcar or have a bike-share membership, it is entirely possible that there may not be a car or a bike waiting for you exactly when and where you need it on short notice. Sharing always implies some kind of risk: that you may not be able to get what you need, that you may not like the person you’re dealing with, that someone may damage your power tool while they’re borrowing it. But for a whole variety of reasons — including financial, environmental and physical-space considerations — we know that more and more people are opting to take this risk with a lot of things no one thought anyone would share 20 years ago.

City 2.0 is available for Kindle and Nook, as well as through the iBookstore. Or download the TED Books app for your iPad or iPhone.

The City 2.0 is an online forum that showcase stories and projects for urban innovation, and also doled out 10 grants for thinkers with great ideas for cities throughout 2012. Here, meet 8 of the winners and hear their fascinating ideas »