Applying the approach of Freakonomics, new research in America shows that parental notification and/or consent laws for abortions succeed in reducing unprotected sex among teenagers. Such laws add to the “cost” of unprotected sex leading to a rational teenage sex drive. The conclusion is supported by new trends in teenage sexual behaviour in America. It appears sex education has meant growing awareness of the degree of risk/costs attached to different forms of sexual activity with lower risk forms becoming more common as well as a growth in virginity. In the UK no parental consent is required and Northern Ireland has teenage pregnancy rates amongst the highest in Europe.