Would a bilingual writer be permitted to do his/her own translation? If so, how would this change the royalties or publishing process for foreign publication?
I can’t answer definitively whether or not you’d be able to do a translation yourself because that would depend entirely on the publisher. Certainly, if we are selling foreign rights, it’s something we could present to the publisher, but many have translators they work with already and might find it easier to continue with the same people.
As for how it would effect royalties or the publishing process, it’s hard to say. Certainly, not hiring a translator should mean the publisher could pay, as part of the advance, what they might traditionally include as the translator’s fee. In other words, it could give us more bargaining power for more money up front. It probably wouldn’t change your royalties much though.
As for the publishing process, one thought did cross my mind while answering this and that’s that it might be better to have the publisher do the translation as they traditionally would so you can be working on your next book. A translation is going to be a time-intensive project and presumably you are already going to be under contract and writing your next title when that opportunity comes up. I know that I, for one, would rather have my client moving forward to build a list rather than continuing to focus on the previous book.