Have we become citizens of an economy, rather than of a society, as the late John Healy warned a few decades ago? The mood is changing in Ireland. As the pace of the Celtic Tiger begins to slow, even to falter, and in the aftermath of the Nice referendum, questions are being asked. Less than a year ago, the sky was the limit for the economy and the Irish appeared strongly committed to the European Union.

Now questions are being asked concerning the kind of society we have created and the kind of people we have become since the Tiger first leapt on the scene. One obvious starting point is to ask about the excluded, the deprived, the disadvantaged, the addicted, those so alienated that they see a solution in suicide.

But if one wants to understand and interpret the social revolution that has occurred within the economic revolution, rooted in the undergrowth from which the Tiger emerged, then there is no more relevant point of departure than that of family change. It has touched the life of each and every citizen.

Throughout much of the 20th century Irish family patterns were distinctive, constituting a major exception to generally prevailing European patterns. Late age at marriage, a high proportion of the population that never married, together with high fertility within marriage and a low level of births outside marriage marked Ireland as a special case.

During a brief span of the last two decades, Irish family life has undergone a remarkable transformation. Ireland is no longer an exception to European fertility patterns, merely at the high end of fertility variation among EU member-states.

Data from the Central Statistics Office show that 30 per cent of all Irish births are to unmarried women. An increasing number of women are the main, and sometimes sole, economic provider for their children.

Family patterns have not only changed for women; they have also changed in marked ways for men and children. More fathers are rearing children on their own. At the 1996 census, fathers and children comprised 3 per cent of all family units compared with 13 per cent of family units composed of mothers and children.

As roles change and intermingle, the process of sharing work and family responsibilities becomes more complex. In an urban society where instant results may be required in the workplace, normal childhood illnesses or a teachers' strike become stress-creating Everests for the working parent. Add in house prices and traffic jams, and the real surprise is that so many cope so well.

As family size declines there are more single-child families. In 1998 first births accounted for 40 per cent of births (21,000 out of 53,000). In the same year only 5 per cent of children were born into families with five or more children, compared with over 30 per cent in 1955.

An increase in permanent childlessness is becoming evident, as has already occurred in continental countries and in the United Kingdom. In the UK, 10 per cent of those born in 1945 did not have a child, compared with an estimated 20 per cent of those born in 1965. In Germany it is estimated that a quarter of women now entering child-bearing years will remain childless.

The economic status of children has also changed dramatically. In the early decades of the 20th century, traditional agriculture benefited from the work of children who helped on family farms and left school at a young age.

With economic development and the extension of formal education, parents tend to have fewer children, but those children spend many more years in the education system.

There have been huge improvements in infant mortality and in life expectancy. Across the 20th century, the infant mortality rate has fallen from 99 to six per 1,000 live births. In 1994 Ireland had the lowest maternal mortality in the world. In 1921 the maternal mortality rate was almost five per 1,000, or close to the death of a mother for every 200 births. Much of these improvements relate to a rise in living standards and improved medical care.

At the other end of the age spectrum, people are living longer and more adults are living alone. More than one in five persons lived alone in 1996 compared with one in 12 in 1926. More than one-quarter of those aged 65 and over now live alone, while scarcely any did so in 1926.

All of these changes suggest the influence of economic factors. The shift from agriculture and a family-based economy towards a male-breadwinner model has been succeeded by the dual-earner model, on the one hand, and reliance on one, often inadequate, income on the other.

Thus a new stratification is emerging between households with two incomes and households with a single income, frequently, but by no means exclusively, derived from a State payment or pension.

Households with children, whether with one or two incomes, must take decisions on child-care, and thus answer one of the most vital questions for any society: "Who will care for the children?"

As families decline in size, as the population ages and as more and more women are in the workplace alongside men, another question is: "Who will care for the elderly?" Are we on the road towards an institutionalised society?

Together with economic factors, issues of values and policy are intertwined. Depending on their strength, economic factors may override preferred values. It may be that some fathers and mothers wish to care for their children while some children wish to care for elderly parents, but economic constraints and realities limit preferred options.

The impact of policy on behaviour is an important ingredient in determining social outcomes. The tax individualisation debate, which erupted following Budget 2000, provides an example where the impact of policy on behaviour was clearly recognised.

In that case the objective was to incentivise workforce participation in a tight labour market. Legal changes which freed up access to methods of contraception provide another example.

Religious beliefs and values are widely regarded as important influences on behaviour. Yet it is a fact that, in a traditionally Catholic Ireland, patterns of family behaviour are indistinguishable in key aspects from those prevailing in what would be viewed as more secular societies.

This is also the case with Catholics elsewhere. For example, American Catholics, for whom divorce is outlawed by their religion, tend to divorce at the same rate as others.

In the struggle between religious beliefs and economic incentives, religious beliefs may have deferred rather than deterred changes in Irish family patterns.

Dr Finola Kennedy is an economist. She is chairwoman of the Housing Finance Agency plc and a member of the board of ACCBank. Her book, Cottage to Creche: Family Change in Ireland, was published yesterday by the Institute of Public Administration