One person left because he wanted to be paid significantly more than his work was worth at the time (according to me, my cofounder, and the 5 people we put in charge of a "pay team" to resolve this). He left, and it was better for him - he took a year off, decided actually the problem was he wanted to be doing charitable work and the money was a way to make up for that gap. He's now working at a charity.

I see it as a loss, but I'm not sure it was an avoidable loss.

Nobody else left because of pay transparency. Before we got our feedback in order, some people left because of feedback about their work, which only came after a round of pay changes, which made it clear to them that they were not doing work that was valued by the company. In those cases it would have been much better for everyone if we had delivered that feedback much more quickly! We're better at this now.

I'm not sure how to answer the first question... we pay good salaries, but we don't have primarily developers so I'm not sure how to compare us to google.

Potential employees get walked through the system we used to come up with what we think their pay should be, and get to see what everyone else's pay is, as a prelude to a chat about what their pay should be. Most are happy to go with our number. Some need more for some reason, and we're flexible about this.

We make the effort to be the first one to quote a number on the basis that typically, in salary negotiations, "the first person to name a number loses". So we deliberately lose upfront to create a situation of trust instead of an opaque, win/lose negotiation where each side is trying to squeeze the other. We haven't encountered a situation where the candidate behaved in a way we considered aggressive or dishonest after we opened the salary conversation in this way. Worth noting that the expected salary range is always advertised upfront with the job.