According to a large European study, the majority of egg donors donate for altruistic reasons, although the financial compensation is also a factor.
The study asked 1,423 egg donors across 11 countries in Europe, including Spain and the Czech Republic. Almost half of all egg donors were donating for altruistic reasons and a further third of women donated for altruistic reasons alongside economic reasons.
Older donors with a higher level of education were more likely to donate altruistically, in order to help others have children.
There are a lot of factors that can explain why some countries have a higher number of donors than others. Thanks to the anonymity of the donors and modern laws regarding Assisted Reproduction, Spain is one of the leading countries in Europe regarding the number of egg donation.
http://www.bionews.org.uk/page_320837.asp