Whether children do have rights, and what, if anything, the state should do about them, is a question that cannot stay off the political agenda.

The media thrive on stories of youth crime, child abuse, or the alleged decline of the family. On a grander scale, we have the 1991 UN Convention on the rights of the child and the 1994 Year of the Family. Now sociologists are getting interested, as shown by this book.

There are big changes affecting the position of children in society. Families are having fewer children, and people are living longer. So more attention is being given to the issues arising from ageing, while children are making up a smaller proportion of the population. However, there is little sign of their value correspondingly increasing. The employment market is also changing as manufacturing industry has declined and jobs have become part-time, insecure or casual. These changes make families, and so children, more economically insecure. Furthermore, where both parents work, neither may be able to spend much time with their children, leading to “time poverty”. It has not been the aim of social policy in Britain to redistribute resources to families with children. Greece is the only other developed country that joins Britain in this policy.

Much of this book consists of detailed studies. I found those which quoted plentifully from the child subjects the most illuminating. Margaret O’Brien, with others, considers what children take to be a “proper” family.This is of particular interest given the publicity about non-traditional family models, with cohabitation, separation and reconstituted families on the rise if not prevalent. Children, however, take as the norm the married couple living with their own children, and are doubtful about variations. Co-residence is crucial, and absent fathers are likely to be excluded and other household members - and pets - included in what children see as their family.

There is also glimpse of a society most of us know little about: Chinese family businesses running take-away restaurants in Britain. Here, children are expected to help out. Indeed, in many non-Western societies it is normal for children to be economically active. But the range of possible participation is great. At one extreme, we hear of children who are withheld from school and moved around when the authorities catch up. At the other, some children contribute while sustaining normal school and later university life. But there does tend to be a loss of free time, of opportunities for social relationships outside the family, and of parental attention unconnected with the business. These children felt both pride and resentment for their parents.

Finally, Peter Selman and Caroline Glendinning tackle that bogey of modern social policy, teenage single mothers. Everyone agrees that teenage pregnancies are undesirable, but opinions are divided about effective ways of reducing them.

The unsurprising answer is that improved educational and job opportunities are most likely to improve motivation to avoid unplanned births. Reductions in sex education, contraceptive advice, social security or housing provision are likely to have the opposite effect. This is what has happened in other countries where such methods have been tried, notably the United States. The lowest unplanned birth rates are in Sweden and Denmark which have liberal policies. The evidence is clear, and so is the moral.

Stephen Barber’s latest book is Weapons of Liberation, published by Faber amp; Faber, Pounds 14.99.