Donor anonymity and secrecy: Where's the evidence?

As his commentary in BioNews 333, 'The HFEA's silence on the need for a father', indicates, Dr Evan Harris MP is a champion of evidence-based practice. During 2004 and the early part of 2005, witnesses to the House of Commons Science and Technology Select Committee in its review of Human Reproductive Technologies and the Law were regularly challenged by Dr Harris - as well as by other members of the Committee - to provide evidence to support their arguments and assertions.

However, it seems that the demand for evidence is a standard the Committee (or at least the half of the committee willing to be associated with its final report) considered to apply less readily to itself than to witnesses. I have in mind, in particular, the Committee's claim that there is 'a powerful argument that the ending of [donor] anonymity would result in a greater likelihood of parents not telling the child because the fear (rational or not) of rejection in favour of an identifiable biological parent outweighs the advantage of having identifying information to transmit' (Vol I, para. 157). Perusal of the transcripts of oral evidence given to the Committee shows Dr Harris to be the architect of this presumption (Vol II, Ev 130).