I'm pretty sure that someone has applied this to the endowment effect and published it somewhere, but I don't have a reference handy. However, the value elicitation process controls for this. Under the process they use, it's rational to state your true WTP and WTA (you'll either miss out on a transaction you would have like to take part in or take part in a losing transaction if you misstate these values). This doesn't prevent it from just being a hardwired thing that humans do, but the gaps do disappear under certain circumstances so that claim seems dubious.