Sticking up for siblings

Why is it that children without siblings in this country are almost twice as commonplace as they were a generation ago? Surely it is a natal no-brainer? Childcare, time off work, the price of an extra bedroom. To cap it all, the Government has slashed child benefit. Little wonder then that more than half of couples with an only child say they cannot afford another. Better to channel those scarce parental resources into giving the best chances to one. Colin Brazier asks whether there is a cost - for parents, society and children themselves.