SHANKAR VEDANTAM, HOST: This is HIDDEN BRAIN. I'm Shankar Vedantam. Earlier this month, a man named Brian Chesky sent out an email that began like this - at the heart of our mission, he wrote, is the idea that people are fundamentally good and every community is a place where you can belong. Chesky is the CEO and co-founder of Airbnb, the online marketplace that connects travelers with people looking to rent their homes. Chesky's email, sent to users across the globe, was a response to concerns about racial bias. Some guests say they've experienced prejudice while trying to book rooms on Airbnb. We first explored these complaints in the spring, in an episode titled "Airbnb While Black."(SOUNDBITE OF ARCHIVED BROADCAST)QUIRTINA CRITTENDEN: The host would always come up with excuses, like, oh, someone actually just booked it. But I go suspicious when I would check back, like, days later and see that those dates were still available.VEDANTAM: Today, we're going to bring you that episode again, with a few updates to reflect changes the company says it's making. We'll begin not with Airbnb, but with another online platform you may have heard of, Facebook. So a few months back, I was on Facebook when a friend request came in.I don't have a great memory for faces and names, so I found myself trying to figure out if I had met this person somewhere. But then, at the back of my mind, I remembered a study. It said my friendship choices on Facebook might be shaped by biases outside of my conscious awareness. Michelle Hebl is a psychologist at Rice University who ran the Facebook study.She designed fictitious Facebook profiles for two men and two women. Both men were named Michael Davis. Both women were Jennifer Davis. All the characters were African-American. The only real difference between the profiles were the photos. One photoshopped version of Michael Davis and Jennifer Davis had lighter skin.The other photoshopped version had darker skin. Mikki Hebl sent out friend requests on behalf of these fictitious characters to more than a thousand people in a big American city. Since these were invented characters, most of the requests were declined. But there was a big disparity in how often whites accepted friend requests from the darker-skin Michaels and Jennifers.MICHELLE HEBL: People were less likely to friend them. They were less likely particularly to friend the dark black males.VEDANTAM: If you follow these kinds of experiments, this finding is disappointing, but not surprising. Using similar experimental methods, researchers have found disparities in the way professors spend time with students, how companies select job applicants for interviews, even how legislators respond to constituents.But something new is happening today. The biased decisions we once made in interpersonal settings are now being made on giant, online platforms, where our actions have the potential to affect many more people. Think about the way you might look for a roommate. Once upon a time, you may have put up a flyer on a bulletin board and talked to people who responded.Today, you might turn to sites such as roommates.com or Craigslist. Raj Ghoshal, a sociologist at Goucher College in Baltimore, recently conducted a roommate study on Craigslist using a technique similar to the one Mikki Hebl used on Facebook.RAJ GHOSHAL: We definitely found a pattern of preference or bias in favor of white-sounding names. So for every hundred replies that a white-sounding name got, a Latino name got about 75, and an African-American name got about 65 or something like that.VEDANTAM: That is a huge difference.GHOSHAL: It's a pretty big difference, right? So if you were African-American, you'd have to spend about one and a half times as much time applying for housing as would somebody with a white name.VEDANTAM: On today's podcast, we're going to delve into what happens when age-old biases rear their heads in a new and growing part of our lives, what's sometimes called the sharing economy.HEBL: It's one thing if I want to discriminate about who I'm going to have over on Friday night to have for dinner or who I want to have sleep over. But it's another thing when my private house starts to become my business.VEDANTAM: The sharing economy - platforms that allow you to hail a taxi, call a babysitter, find a room on Airbnb - rely on making what used to be business exchanges into semi-personal transactions. Your Uber driver sees your name and photograph. You see your driver's name and photo. It's supposed to increase trust, and there's every reason to think it does. But it also does something else.HEBL: When you give people names, then you give people information about your ethnicity, you give people information that they can use to look you up and figure out more cues (ph) about you. And that becomes problematic.VEDANTAM: Mikki was on a ship when I interviewed her. She's teaching a semester at sea. During the long voyage, she says, her students tell her about the many online platforms that they're using.HEBL: There's a website called care.com, and it's a babysitting website where people advertise themselves as babysitters. And they have to put a picture of themselves on, so you can think about how, again, maybe I don't want a babysitter that is of that race. Maybe I don't want a babysitter that is of that gender. And so you begin to see where this very subtle type of discrimination can be very systemic.VEDANTAM: The sharing economy is unleashing new possibilities in our lives. These platforms allow us to meet more people, visit more places, get more connected. I'm personally a fan of many apps. But it also seems clear to me that these platforms provide a mechanism to amplify our collective bias.What's especially insidious about the biases on these platforms is that their consequences are largely hidden. If your request to be a babysitter gets turned down, you have no way of knowing if this was driven by racial bias. So I asked HIDDEN BRAIN producers Maggie Penman and Max Nesterak to take a few weeks and try to find people who are personally affected by such biases.They decided to focus on an important new part of the sharing economy, Airbnb.MAGGIE PENMAN, BYLINE: Imagine you're going on vacation with some friends. You do a quick search online, find a few hotels in the city you'd like to stay in. You pick one, ideally with a hot tub, and enter your credit card information. Great, you think - all set.MAX NESTERAK, BYLINE: But then you get an email - we're sorry, but the dates you just booked aren't available after all. They were listed by mistake.PENMAN: Now, if this happened to you once, you might chalk it up to a weird website glitch. But if it happened to you over and over, something would start to feel funny. You might start to feel like it's something about you that's making these hotels suddenly unavailable.NESTERAK: This is exactly how Quirtina Crittenden felt when she would try to use Airbnb to book vacations with her friends. She would find a house that was listed as available, send a booking request...CRITTENDEN: And I would get declined all the time.PENMAN: Quirtina got a bunch of similar responses.CRITTENDEN: The host would always come up with excuses, like, oh, someone actually just booked it, or, oh, some of my regulars are coming in town and they're going to stay there. I just haven't updated my calendar. But I got suspicious when I would check back, like, days later and see that those dates were still available.NESTERAK: Quirtina's black, and this is relevant because, on Airbnb, both hosts and guests have their names and photos prominently displayed on their profiles.PENMAN: And this is actually one of the platform's selling points. It's supposed to make these transactions between strangers feel less anonymous and less scary.NESTERAK: But it also made Quirtina start to wonder if these rejections had something to do with her race.CRITTENDEN: And my name is Quirtina. I have a very black-sounding name, and I also had my photo. So I'm very clearly a black woman.NESTERAK: And when she looked at the reviews that previous guests had left for these hosts...CRITTENDEN: I never saw anybody who looked like me.PENMAN: So Quirtina did what any good millennial does when they're frustrated - she took to Twitter.CRITTENDEN: And I was just venting my frustrations, and I just included a lot of screenshots of the messages that I was getting from people. And I put the hashtag #AirbnbWhileBlack.NESTERAK: She started hearing from lots of friends who had similar experiences.CRITTENDEN: The most common response that I got was, oh, yeah, that's why I don't use my photo - like, duh (laughter) - like I was the late one.NESTERAK: And one friend who had hadn't.CRITTENDEN: One of my friends who's actually black, he responded to me and said, well, I've never had an issue. And then he went back and checked his profile, and I guess he never wanted to use his photo. So he realized that the whole time he had been using the photo of some random white guy from our school. And so he's like, oh, maybe this is why I've never had an issue.PENMAN: So Quirtina decided to tweak her profile.CRITTENDEN: I shortened my name to just Tina, which is a name that I go by in work and in other settings. And I changed my photo to a landscape. Ever since I changed my name and my photo, I've never had any issues on Airbnb.PENMAN: Now, it's impossible to say exactly why Quirtina was rejected by those specific hosts.NESTERAK: But a recent study shows racial discrimination on Airbnb is widespread.MICHAEL LUCA: I'm Michael Luca. I'm a faculty member at Harvard Business School. I'm an assistant professor of business administration.PENMAN: Michael Luca and his colleagues, Benjamin Edelman and Dan Svirsky sent out fake Airbnb requests to real-life hosts.LUCA: So we sent out 6,400 requests to stay with people, and we kept every request the same.NESTERAK: The only thing that was different about the requests - the profiles attached to them either had African-American-sounding names or white-sounding names.PENMAN: So, like, does Brad get the same number of responses on Airbnb as Jamal?LUCA: We could see that there was a very different response rate and acceptance rate for African-American guests relative to white guests. Having an African-American name leads to roughly a 15 percent lower chance of being accepted as a guest on Airbnb relative to having a distinctively white name, holding all else constant.NESTERAK: To put this in perspective, Airbnb isn't some little startup anymore.PENMAN: It's one of the largest players in the hotel industry worldwide. In 2015, more than 2 million listings were offered on the platform from hosts around the world. That's nearly four times as many rooms as the Marriott Hotel chain.NESTERAK: You can even rent a castle.PENMAN: And it's not just vacation rentals. People are finding housing on this platform for months at a time, so discrimination on Airbnb is discrimination in the housing market.NESTERAK: Michael Luca and his colleagues think people could be discriminating without even knowing it.LUCA: Bias, for a lot of people, is something that is accidental.NESTERAK: What Michael Luca is talking about is unconscious bias - these hidden associations we have that affect our behavior without us realizing it. It's unlikely that most hosts are saying to themselves, I'm going to reject this person because I don't want to rent to a black person.PENMAN: I mean, maybe some people are intentionally discriminating.NESTERAK: There are probably some people like that, but Michael Luca suspects the way Airbnb's platform is designed is triggering the associations people have of some racial groups. So because names and photos are the first thing people see, it may also be one of the first things they consider, consciously or unconsciously, when choosing a place to stay. He and his colleagues looked at five major cities in the U.S., and discrimination was happening across the board.LUCA: We saw there was discrimination among cheap listings, expensive listings, in diverse neighborhoods, in homogenous neighborhoods, among white hosts and among African-American hosts.DAVID KING: I actually spoke to Mike Luca last week.PENMAN: That's David King, the brand-new director of diversity and belonging at Airbnb. He knows this is a problem, and he wants Airbnb to be a leader on fixing it.KING: There is a racial bias in platforms, and we are working with Mike Luca and any other external interested parties in how do we address and fix this problem?PENMAN: David King also pointed out there's a lot of opportunity for Airbnb to do good. They're bringing together people from all different backgrounds who wouldn't normally meet.KING: We've done some recent reports in Chicago and New York pointing out that underserved communities, especially African-American communities, have benefited quite a bit from our platform, usually in neighborhoods where there are few hotels.PENMAN: One of those neighborhoods with few hotels lies east of the Anacostia River in Washington, D.C. There are lots of big-box stores and empty lots, but also row houses and families that go back generations. We went there to visit Airbnb host Synta Keeling.SYNTA KEELING: Hi. How are you?PENMAN: Synta owns a three-story townhouse in a new development. She rents out two rooms on Airbnb. There's a fitness room, cable and high speed Internet, solar panels and slippers for all of her guests.I love the slippers, first of all. So. everyone...KEELING: (Laughter). Ikea.NESTERAK: Synta is a super host, and we're not just saying that because of the slippers. It's an official designation she's earned from Airbnb based on positive reviews from her guests, her responsiveness to booking requests and the fact that she's never canceled a booking. It shows Airbnb travelers she's been verified as a good person to stay with. Synta says, as a black host in a black neighborhood, that's important. She feels like she gets held to a higher standard than other hosts.KEELING: This neighborhood's called Capitol View, and it's 98 percent African-American, double-digit unemployment.PENMAN: We asked Synta whether her race and the racial composition of her neighborhood made it harder to get guests. And she said...KEELING: Absolutely (laughter). Yeah, no, I had one - I've had some instances where people ask me all these questions about, is it unsafe in this - and I'll say, you know, I'm a black Filipino woman. I take - we take great pride in our community. This is absolutely a good place for you stay. And I'll say those things, and then there'll be crickets. They'll just not book.PENMAN: But Synta also said there were great things about Airbnb. For one thing, it brings her a steady second income.NESTERAK: Airbnb brings business to the stores and restaurants that don't typically benefit from the tourism industry. Airbnb's slogan is belong anywhere, and there's some truth to it.PENMAN: Synta Keeling told us a story about one of her guests that drove this message home. He came back from being out for the day and told her...KEELING: I took the bus back, and I was the only white person on the bus, and it was all these black people. And I asked myself, were they going to hurt me? Am I unsafe? And then I realized they weren't hurting me and nothing was going to happen to me. Like, they were just sitting there normal.And he - and he was saying this in a way that he - it was like he mentally realized the horridness of what he was saying. But at the same time, he was just being honest about what he was thinking and that he arrived to the stop and just said come off. And, like, nothing had happened to him, and there was just this shock.NESTERAK: Synta says she knows that some people won't rent from her because she's a black host in a predominantly black neighborhood.PENMAN: But here's the thing - she's glad those people don't book with her.KEELING: The strange thing about Airbnb - makes it tough - is I really don't want a racist guest in my house (laughter) because I don't - I live here in this space, so I don't need to feel uncomfortable, you know, the other way. But if - if you just feel like, well, you know, maybe I'll give this a shot, then I'm willing to be open-minded.PENMAN: The fact is Airbnb is not the same thing as a major hotel chain. Hosts have discretion on the platform, but guests don't have the same legal recourse as hotel customers if they feel they've been discriminated against.NESTERAK: We spoke to a couple lawyers for this story, and the legal picture is a little murky here. It isn't clear who, if anyone, is liable for discrimination on a web-based platform.PENMAN: So Airbnb does offer this opportunity to experience different cultures, to meet people you wouldn't normally meet. But sometimes, hidden bias is getting in the way.NESTERAK: And people like Quirtina and Synta are paying the price.VEDANTAM: Producers Maggie Penman and Max Nesterak. When we come back, Maggie and I are going to talk about the steps Airbnb is taking to address these issues since our story first aired in April. Stay with us.(SOUNDBITE OF MUSIC)VEDANTAM: This is HIDDEN BRAIN. I'm Shankar Vedantam. We're exploring the many ways in which the sharing economy might allow hidden biases to flourish. As apps in the sharing economy become an increasingly large part of our lives, they have the potential to create great disparities - the latest twist on the age-old problem of cabs that don't stop to pick up black people.A lot has happened since our story first aired. The hashtag Quirtina started, #AirbnbWhileBlack, went viral. News organizations all over the country picked up the story. Airbnb hired a team of heavy hitters to address these issues, including Laura Murphy of the ACLU and Eric Holder, the former attorney general.They conducted a 90-day review to look at the problem, and they've just released a report announcing changes based on their findings. I'm in the studio now with Maggie Penman to talk a little bit about this issue and get an update on what Airbnb is doing. Hi, Maggie.PENMAN: Hey, Shankar.VEDANTAM: Back when we aired this episode, Maggie, Airbnb was already offering a way for hosts and guests to get around possible prejudice.PENMAN: That's right. The platform has long offered this feature called instant book. And normally when you want to book a place on Airbnb, you have to put in a request, and the host accepts or denies it. But with instant book, you are accepted immediately. And one of the big changes that they just announced is the company is planning to make this feature much more widely available.VEDANTAM: Let me try and understand this. What would incentivize hosts to offer this option?PENMAN: Well, it's much more convenient for guests, so I think you're more likely to get your place booked. And it can also be more convenient for hosts. Let's say you're renting out your whole home. Instant book might just be easier for you. Max and I talked with someone who used this feature to circumvent what he saw as discrimination. Very much like Quirtina Crittenden, Reid Kennedy (ph) is African-American, and he says he was having trouble getting his requests accepted.REID KENNEDY: And so after being rejected - I think in that case four times within the same day for reasons, again, that weren't specified - I started to see a pattern.PENMAN: He complained to Airbnb, and Airbnb gave him a credit. But, of course, if your problem is that you are not able to book a place, getting a credit to book another place doesn't really help you very much. So he tried the instant book feature.KENNEDY: And ironically, the host was a black man who may have been using the instant book feature for the same reason I was.PENMAN: Airbnb said in their statement that they hope to have a million listings available for instant book by January. And they think this is going to start to address some of these problems.VEDANTAM: So in some ways, this could be a design solution for the psychological problem of bias.PENMAN: Right. And this is similar to a solution Michael Luca came up with. That's the researcher at Harvard. He worked with the computer scientist to develop a Google Chrome plugin called Debias Yourself, and it removes photos and names from people's profiles so users can't discriminate, even by accident. He said he actually got this idea from orchestras.It used to be that orchestras were overwhelmingly male, and many people might have thought, oh, well, maybe there are just more male musicians, or maybe they're just better than female musicians. But then this started to shift, and orchestras became more and more gender balanced.When a couple of researchers tried to figure out why, they found that many auditions had switched to being blind, which meant judges had gone from watching the performers to just listening to them play from behind a screen. Mike Luca thinks that Airbnb should be doing the same thing on a larger scale. And this step of increasing instant book is sort of moving in that direction.LUCA: One of the things that I love about the digital world is that it gives us the opportunity to choose exactly where to put screens and where not to put screens. So I think we have a host of new decisions that we can make as market designers that will decide how inclusive a society we have or how much discrimination we want to encourage or allow.VEDANTAM: Here's the interesting thing, Maggie. One of the attractive things about Airbnb and the sharing economy in general is that people don't feel like they're walking into an anonymous place. You know, they feel like they know the people with whom they're renting a home. So there's some balance between hiding information from people and revealing information that can exacerbate these biases.I remember talking to Raj Ghoshal. This is the sociologist who did the study looking at racial disparities in roommates searches. He told me that maybe the focus should be on playing up some kinds of information.GHOSHAL: Perhaps colleges and universities can play a role in this. And perhaps websites like Craigslist or roommates.com could do more to actually, like, frontload information about people's living habits or cultural identities - what time people get up and go to bad, what level of messy they are, that sort of thing - rather than immediately hitting people over the head with somebody's name, just because, you know, all the evidence we have, evidence from other studies, just suggests that, like, race and names is such a - such a powerful signal to people that we probably don't actually want it to be the first thing or the immediate thing that people see and are - and are deciding by.PENMAN: That's a really interesting point. And I think that's why Airbnb hasn't done what some people were suggesting, which was to totally eliminate names or photos, because that lack of anonymity is definitely part of the appeal.VEDANTAM: Is the company doing anything else to try and eliminate discrimination?PENMAN: Yeah. So in addition to building up that instant book option, they're also asking everyone who uses the platform to commit to a stronger non-discrimination policy. And they're working on an anti-bias training that's going to be offered on the site. But the most radical thing they're doing is implementing what they call an open-doors policy.If any person, anywhere in the world feels they can't get a booking because they're being discriminated against, Airbnb will find them a similar place to stay. If there isn't anything available on Airbnb, they'll find accommodation for them elsewhere. So this is clearly an effort to address concerns about discrimination, but a policy like this would really only help guests who are having trouble booking a room, not hosts who are trying to rent a room.The company said in the statement this is the beginning, not the end of their effort to combat bias, so maybe in the coming months we'll see features or policies designed to help hosts, too.VEDANTAM: That's interesting. Thanks so much, Maggie.PENMAN: Thanks, Shankar.(SOUNDBITE OF MUSIC)VEDANTAM: This episode of the HIDDEN BRAIN podcast was produced by Maggie Penman and Max Nesterak. Our supervising producer is Tara Boyle. Renee Klahr manages our Facebook and Twitter pages. Check out the hashtag Quirtina started, #AirbnbWhileBlack. An incredible conversation has unfolded there over the last few months. I'm Shankar Vedantam, and this is NPR.(SOUNDBITE OF MUSIC)VEDANTAM: Hey, listeners - quick request. We're thinking of putting together an episode about people who break barriers. Are you a woman who's had to deal with a glass ceiling, a man who's questioned for working in a field that's mostly female or the only person of color at your school? Tell us a story of what that's like. Call us at 661-772-7246. That's 661-77-BRAIN.SAM SANDERS, BYLINE: Hey, Sam Sanders here from the NPR Politics Podcast. Mark your calendar. Monday, September 26, is the very first presidential debate. And the next morning, we are inviting you to skip the cable news hangover and get caught up with us. We'll have new podcast episodes the morning after every single debate, so you'll know what happened and what it means by the time you get to work or class or finish walking the dog. Whatever your morning routine, make us a part of it. The NPR Politics Podcast - subscribe or listen on the NPR One app. Transcript provided by NPR, Copyright NPR.