Professor Deirdre Madden:

Yes. I think I mentioned in my presentation earlier whether, when we think about altruism, it necessarily applies in, for example, family relationships, whereby somebody might be put under subtle or maybe even not-so-subtle pressure to act as a surrogate for a sister, cousin or family friend. That kind of thing can be very pressurising as well. To me, therefore, money is not the issue; it is about whether the person has the capacity - we must presume they do - to enter into this arrangement, knowing fully what they are getting involved in without any threat or coercion, economic, family or otherwise. That, to me, is the most important thing when we think about exploitation rather than the money.