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Singapore govt dating app uses Gale-Shapley stable marriage algorithm

466 points · 499 comments · rzk

  1. abeppu · · focus · HN ↗
    So on the one hand it's nice to see when a cool algorithm or framework is used IRL.

    On the other hand, actually applying a 'stable marriage algorithm' to people makes a bunch of assumptions which are worth interrogating:

    - Do people actually know what they want even in the short term?

    - Do people's preference change meaningfully over longer periods of time?

    - Does your preference _upon reading people's profiles_ have any strong relationship to your preference after spending any amount of time with them?

    The property that right after being matched, no one could have matched with someone whose profile they preferred more does not mean that this will create stable relationships.

    1. justonceokay · · focus · HN ↗
      Least they are using an algorithm that has the intended purpose of matching people. For profit dating apps are more interested in keeping you coming back then they are in creating successful relationships
      1. missedthecue · · focus · HN ↗
        This is an extremely common sentiment I see online - that there is some conspiracy to keep people single to reduce subscription churn. I have run two dating apps (my own apps, not working for a company), and what I found through trial and error was that no matter how many levers you pull and tweaks you make, a lot of it is simply user-behavior problems, not a tech or product design problem. There is no reliable way for a dating app to only serve users non-committal matches for example. The reason someone's matches aren't committal is because they don't want to commit.

        The thought experiment I usually pose is to ask what you think a free, open source, and community supported dating app would change. The answer is "not much".

        1. nostrademons · · focus · HN ↗
          Note that it's possible for dating problems to be user behavior problems in a way that is suits the profit motive of dating sites, without any conscious intent from anyone in the ecosystem.

          Model a world where everybody's self-perception of their mating value is just a little bit higher than their actual value - in other words, one not too far off from reality. Some segment of this population will drop their standards in the face of repeated rejection, and then eventually find a partner because of this. Their "lowered standards" become an accurate self-perception of reality. But some segment of the population will be unwilling to do this. They have a problem - they cannot find a partner no matter how hard they look.

          A problem creates a market. People who can't find a partner turn to dating apps to find a partner - some may pay, and a lot more will click on ads. There's a decent chance that dating app management isn't consciously optimizing for failure in dating and success in clicking on ads. However, all the apps that are good at finding partners for their customers find that their customers disappear, while the apps that are good at getting people to click on ads generate huge amounts of revenue and take over the market. Which is entirely composed of people who don't actually want to find a partner, anyway, because those people who care more about the outcome of finding a partner will usually drop their standards enough to find one.

          The same dynamic applies in many other markets. Evolution and selection bias > intent and intelligent design. The market ends up composed of people who can't achieve the ostensible purpose of the market, largely through their own actions, because people who can drop out of the market. Happy people often go through life with very few transactions: they might change jobs a couple times early in their career before finding a boss and job they're happy with and staying there until retirement, or they date around a little and then find a partner they marry for life, or they might rent a couple apartments before buying a house, renovating once, and then staying in it for 40 years. The transactions are overwhelmingly composed of people who are dissatisfied, because that's why they're buying things.

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