Interesting stuff, thanks; looking forward to the rest of the series.

As an aside, this makes the benefits of being able to rely on trust most of the time very apparent. Jack and Jill can coordinate very simply and quickly if they trust each other to honestly disclose their true value for the project. They don't even need to be able to trust 100%, just trust enough that on average they lose no more to dishonesty than the costs of more complex and sophisticated methods of bargaining. (Which require more calculating capacity than unaided humans have evolved.)