One of the more depressing social trends is that, since the 1970s, fewer and fewer Americans have told surveyors that "most people can be trusted."

So it's interesting to note that trust appears to be a primary glue holding the sharing economy together. According to a survey of U.S. consumers by PricewaterhouseCoopers (PwC), 89 percent of those familiar with the sharing economy agreed it was based on trust between providers and users. Sixty-three percent thought the sharing economy was more fun, and 73 percent agreed it builds stronger communities. And PwC estimates the sharing economy could hit a massive $355 billion in global revenues by 2025.

So could AirBnB, Couchsurfer, Uber, Lyft, Tidal, Zipcar, Car2Go, Feastly, and all the rest help repair America's fraying social fabric? Maybe.

First off, this actually isn't a new thing. Throughout human history, various societies and cultures that would normally have nothing to do with one another have been forced into contact by the rise of new trade routes and the expansion of economic activity. They may find each other strange or off-putting, but if there's a way they can do a deal and make a buck, it behooves them to figure out a way to get along. Markets throw people together, and in that sense they've been a force for pluralism, tolerance, and diversity.

But as PwC notes, "Consumers are more interested in affordability and convenience than they are in building social relationships with providers or other consumers." The happy side-effect of markets may be an enriched community, but the driving engine remains the profit motive. That's a dangerous engine that can go awry, creating a race to the bottom that offers ever cheaper goods and services at the cost of ever more threadbare compensation for workers. Meanwhile, the social fabric gets ripped up and a small oligarchy at the top makes out like bandits.

Of course, PwC just wants to help companies get an edge. But we could also use its observations as a framework for making sure the sharing economy serves to repair society rather than atomize it further.

To start, we need to make capital easier to own. Critics worry about the sharing economy's emphasis on access over ownership, but PwC's survey suggests that's a misread. After all, being a provider in the sharing economy is an encouragement to buy property, be it a car or a home or whatnot, and maintain and husband it over time. The report argues that if market forces play out as expected, the quality of service and the durability and resale value of capital involved in the sharing economy could outpace price as the determining factor. Sharing economy providers are also distributed surprisingly evenly across the economy, with roughly half above and half below the median income.

Ultimately, the goal shouldn't be "more ownership," but an ecology of ownership and access that's both more efficient and conducive to community bonds.

There are some big-picture changes we could make to tax policy to try to break up the ownership of capital and distribute it more broadly. At a more nitpicky level, we should make it easier for people to get tax write-offs for the capital and expenses they take on as providers. And tax incentives could nudge capital owners to participate more: for instance, there's an app called Storefront that could boost local artisans and retailers by helping them share floor space with bigger and established outlets.

We should also figure out ways to encourage cooperatives, worker-ownership, and other forms of more local investment — so that, say, a city can collectively own its car-sharing network the same way the Green Bay community owns the Packers.

Next, we need to make sure the sharing economy doesn't create a society of shut-ins, anonymously ordering all of life's needs through Amazon, having them delivered by a faceless provider, and gaining more free time that simply gets chewed up by jobs and telecommuting. This boils down to two things: giving everyone some breathing room from the demands of the job market, and making sure incomes are high enough that hiring people for these sorts of petty tasks is prohibitively expensive. That would then increase the economic incentive for you and your friends to go to the grocery store together in an Uber ride or a Zipcar, for example.

Nationally mandated paid leave and paid vacation, strengthened overtime rules and a shorter work week would all help, as would policy changes to strengthen unions in the sharing economy. Finally, bulking up unemployment benefits, food stamps, and the like will make it easier for workers to turn down jobs they don't want, and to demand higher wages.

Finally, we should try to ensure that the sharing economy creates lasting relationships. For instance, 69 percent of people told PwC they don't trust companies in the sharing economy until someone they trust recommends them. And studies suggest that while the sharing economy can create an initial ferment of new and unexpected connections and relationships, trust begins to erode as more comments and feedback, positive and negative, build up in the system. So individual companies should think about ways to encourage Uber riders to keep returning to the same trusted driver, Feastly users to keep returning to the same cook, Storefront users to keep returning to the same spot, AirBnB and Couchsurfer users to keep cycling through the same networks, etc.

The sharing economy, like the broader market, is ultimately amoral. It can make society worse, or it can make it better, depending. What "better" is will always be a social, political, and moral question. And it will always be up to all of us to collectively answer that question, and to then put the norms and policies in place to push markets towards the answer.