A staggering 40 per cent of marriages are now doomed to end in divorce, despite the bad press: divorce is bad for your health, bad for your purse and particularly bad for your children. In the course of researching a book I have written with Fiona Shackleton, a divorce lawyer, I have been continually surprised by the misery that divorce inflicts upon families - often more, it seems to me, than the misery of an unhappy marriage.
That is not to say that people should never divorce. Any couple locked in a violent relationship would be better off without each other. But for the vast majority of couples with children, divorce will bring a whole new set of problems.
I am married for the second time, now with two young children - and they have changed things utterly. I have come to the conclusion that unless you are young and childless, or fabulously wealthy, divorce should not be a consideration until your youngest child is, say, 16 and has an independent future in sight.
Few people who embark on divorce proceedings realise how much they are likely to suffer financially. A typical example is a couple with two young children who live in a three-bedroom house. There is not enough money to buy two establishments; the mother may not work because she is looking after the children, so her husband has to continue to support his wife and children, even though he no longer lives with them.
The mother and children could possibly move to a smaller house, releasing a little capital to reduce the mortgage, although a good chunk of that will be swallowed up in house buying and selling fees. The husband will still have to pay for himself to live elsewhere, even if he is subsidised by another woman.
The real financial troubles will begin if the husband wants to remarry. When he has to support a second wife as well, he may be able to have his maintenance payments to his first wife and the children reduced, particularly when his second wife has a baby. If the payments to his first family are inadequate, that family may have to depend on benefits just to eat. Most two-parent families - 89 per cent - rely mainly on one or both parents' earnings; 66 per cent of single-parent families rely on social security benefits. Not surprisingly, within two or three years of a divorce, nearly 50 per cent of non- resident parents (mainly fathers) have lost touch with their children - 750,000 British children never see their fathers.
If a man's second wife has a good income, his first wife can ask the court to increase the maintenance paid for herself and the children because her former husband's own personal needs are shared with his second wife. Little wonder that many second marriages founder because the second wife believes she is working solely to support her husband's first wife and children.
Many couples who divorce later regret the decision. A small survey carried out in Bristol in 1988 among divorced people showed that 51 per cent of men and 29 per cent of women would have preferred to stay together. For their own health and the well-being of their children, they would have been better off still married.
A number of studies have shown that divorced people are more likely to contract chronic illnesses and die earlier than people who remain married. Recent research by Dr Kathleen Kiernan, of the Family Policies Study Centre, research organisation, shows that the offspring of divorced couples do less well at school and are likely to be more aggressive and disobedient; those who live with step-parents suffer even more.
So why do we continue to do it, when the vast majority of divorced couples with children face years of financial difficulties, on top of all the emotional upheaval that the legal process, single parenthood, remarriage and step-families cause?
For a start, 'Till death us do part' is nowadays interpreted more as 'Till death of our relationship us do part'. And there are fewer deeply committed believers who will be sustained by their religion during difficult patches in their marriages.
Duncan Dormor, who works for the charity One Plus One: Marriage and Partnership Research, points out that people who have started divorce proceedings are often confused and do not really know why they are doing so. But divorce seems so much the norm that often when a couple hit the first rocky patch in their marriage, they see no other solution.
Three-quarters of divorces are still fault-based. In other words, to get a divorce one party blames the other for unreasonable behaviour, desertion or adultery. This is much quicker than the alternative, which is to live apart for two years. The woman is more often the petitioner, with middle-class women more likely to cite adultery, while women in lower socio- economic groups tend to cite unreasonable behaviour.
Women's expectations of marriage have changed dramatically in the last two decades as they have become economically independent. There is now less emphasis on their 'duties' in a marriage and more on rights and individual development, so women are less willing to sacrifice themselves to keep their marriages going. But if a marriage breaks down, the paradox is that women who are divorced are even more tied by children to the home - both economically and emotionally - than when they were married.
Perhaps one of the most important reasons for divorce given by couples is that their children were unable to cope with constant arguments and that, on balance, the damage to them has been minimised by the divorce. But there is no evidence to show either that children are better off living with two parents who are staying together solely for their sake, or that they are better off with one divorced parent, because it is impossible to research the subject objectively.
There is research, however, indicating that when parents genuinely intend to share the care of their children, divorce need not cause them undue suffering. Ingrid Lund, at the Institute of Education, London, found that children whose parents separated without acrimony did as well as those from stable families. The most critical period is immediately before the couple separate and during the divorce proceedings. If children are handled sensitively during this time they have a good chance of surviving the process relatively unscathed. A child who realises that, while his or her parents no longer want to live together as man and wife, this decision does not affect their feelings as father or mother, will fare better than a child who is used as a pawn in the parents' emotional games.
I can think of several couples who are divorced with teenage or younger children who have roughly the same arrangement: the mother and children live in one house, the father (with or without a new partner) in an adjacent street. The parents look after the children on alternate weekends, and the father spends at least two nights a week with the children, helping them with homework and putting them to bed. The impact of the divorce on the children has thus been minimised.
Finding such a modus vivendi, whatever the cause of difficulties in the marriage, may be preferable in the short term to divorce. 'Staying together for the sake of the children' is not necessarily a burden for ever. Even those whose relationships are undermined by infidelity often find that if they hang on, hoping an affair will blow over, their patience is rewarded.
Unhappy couples who go to counsellors are often surprised that it is not dramatic changes that make a marriage work again, but small compromises. In this way they may be able to keep the marriage going, at least while their children are growing up. Now that we all hope to live into our eighties, people who delay divorce until the youngest child is on the point of leaving home could still have 30 years of their lives left to enjoy.
'The Divorce Handbook', by Fiona Shackleton and Olivia Timbs, is published by Thorsons on 10 September at pounds 6.99.