This illustration can only be used with the Sarah Smith story that originally ran in the 10/233/2015 issue of National Journal magazine. Neil Webb

New York University Professor Ingrid Gould Ellen has an idea she thinks could help get more low-income families money for housing subsidies: Take lessons from sharing-economy success stories like Airbnb and apply them to the world of affordable housing. I recently spoke to Ellen about her idea. Our exchange has been edited and condensed.

What problem would this idea address? How is this different from what’s already in place under Section 8?

We live in a world where three-fourths of eligible households in the U.S. don’t receive any housing subsidies due to lack of resources. The idea is to make subsidy dollars stretch further with sharing. We’d have policies that make sharing homes easier, or sharing subsidies possible, and we’d relax building regulations. Housing authorities currently can allow Section 8 voucher-holders to live in shared living arrangements, and to pay a prorated share of the rent, but many housing authorities avoid offering this option because of worries about liability and a lack of control—what if other members stop paying their share of rent? Sharing could be messy, but we have little experience with it. The idea is to encourage more housing authorities to embrace sharing.

What kinds of sharing would make sense with housing subsidies?

One is learning from the Airbnb model, which suggests there’s some excess capacity in our housing stock, and people are willing to take in boarders on a temporary basis, as it gives them additional income. Especially in higher-cost cities. I think it’s an interesting question: Would people be willing to take on boarders on a more permanent basis, rather than visitors? There’s also a communal model—smaller apartments with a shared communal space. You could think about sharing subsidies themselves. Because you’re only renting a room, say, in a house, it would require less subsidy, and we could theoretically make the dollars stretch to more families.

How would people get matched for this sharing program?

It could be a platform not unlike Airbnb’s platform—New York City used that kind of platform to match people after Superstorm Sandy. Or it could be a Craigslist kind of format. For example, many older adults live in homes with extra space. They could often benefit from the additional income they could earn from renting out those spaces and the companionship—and perhaps modest assistance—that new residents would offer. Yet entering into such arrangements with strangers might be daunting and even frightening. So there may be room for organizations to help match older adults with extra space with responsible young families and adults struggling to make ends meet in high-cost cities.

Would this definitely be better for the families in need of housing subsidies?

I think we don’t know—it requires research. It depends on what the effects are for those families who are basically doubled-up. How much better is that than not having any assistance at all? What we don’t know is what the long-term effects of doubling-up are on children. That’s a critical question we need to learn more about.

What would it take to make this happen?

It would take some adjustments to housing-quality standards—like limits on how many people can live in an apartment based on the number of bedrooms. I think we should think about relaxing some of those rules—but with caution so we can monitor the impact. Then there are rules to the subsidy programs themselves that we might want to be more flexible about. It could be that we make it easier for households to use their vouchers in home-sharing situations. It’s technically allowed by the program, but many local authorities choose not to allow it.

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