demography « Top of the Campops: 60 things you didn't know about family, marriage, work, and death since the middle ages

Top of the Campops: 60 things you didn't know about family, marriage, work, and death since the middle ages

Posts Tagged ‘demography’

Three score and ten?

Thursday, August 15th, 2024

Romola Davenport & Jim Oeppen

Campop’s studies of mortality suggest that, in England, average life expectancy at birth varied between 35 and 40 years in the centuries between 1600 and 1800. It is a common misconception that, when life expectancy was so low, there must have been very few old people. In fact, the most common age for adult deaths was around 70 years, in line with the Biblical three score years and ten. So what does ‘life expectancy’ actually measure?

George Paul Chalmers, “An Old Woman”, National Galleries of Scotland.

What is life expectancy?

To understand life expectancy, we can imagine a group of 1,000 babies born at the same time. We can measure how long each one lives. Figure 1 shows the lifespans for these infants as horizontal bars that indicate the length of life, arranged from top to bottom in order of lifespan. Their lifespans follow the pattern of mortality in England in 1841.

Figure 1. Lengths of life and percent remaining alive of 1,000 babies born into a hypothetical population in England and Wales in 1841. Source: Human Mortality Database.

As you can see, in 1841 a lot of children died in the first five years of life. Of 1,000 babies, 138 (nearly 14 percent) died before reaching their first birthday. By age five, over a quarter of the original 1,000 babies were dead.

However, after the first five years, the rate of attrition eased. Children who made it to their fifth birthday had a 50:50 chance of making it to their 60th birthday. Of the original 1,000 babies, 38 percent survived to age 60, and nearly 10 percent to age 80.

So why was life expectancy only 42 in 1841? Because life expectancy is the average of all the different lengths of lives in the population. When mortality is high in infancy and childhood, then many of these lives are very short, and these many short lives really bring down the average age at death.

Richard Tennant Cooper, “A Ghostly Skeleton Trying to Strangle a Sick Child; Representing Diphtheria”. Image: Wellcome Collection.

Calculating life expectancy

To calculate life expectancy, we take all the ages at which people died, add them up, and then divide by the number of people. For example, if we had a ‘population’ of two people, one of whom died on their first birthday and the other who died on their 100th birthday, their average life expectancy would be their ages at death added together and divided by two (101/2 = an average life expectancy of 50.5 years). But neither individual died in their 50s, or anywhere near their 50s. The average is not a good indicator of mortality risk in this case, because the length of life is so variable in this population.

On the other hand, if we have a population of two people, one of whom died on their 80th birthday and the other on their 100th, then average life expectancy would be 90 years, a much more representative estimate of average years lived. The latter case is much more like most populations in the world today. As life expectancy has risen, the benefits have been felt first at younger ages, and death has become increasingly concentrated in late adulthood.

Changing life expectancy over time

In the early 1600s (the first period for which we can calculate life expectancy in the English population) there was a huge peak of deaths in infancy, but then deaths were strung out across the whole life course between birth and 110 years of age. That is, the length of life was very unpredictable in the 1600s, and the risk of death was fairly high at all ages.

David des Granges, “The Saltonstall Family”, c.1636–7. The painting has been interpreted as depicting Sir Richard Saltonshall and his two wives and children. His first wife Elizabeth Basse, in the bed, died in 1630 leaving two young children, and Richard married Mary Parker in 1633. Image credit: Tate.

By 1800, this pattern had begun to shift. Mortality had become more concentrated at the oldest and youngest ages. In personal terms, this meant that fewer young children experienced the loss of their parents, fewer young adults were widowed, and fewer elderly parents experienced the untimely deaths of their adult children.

By the 1960s, deaths in childhood and early adulthood were relatively rare, and most people could expect to live into their 60s, 70s or 80s. Life expectancy was around 72, and this is a much better reflection of the ages to which most people could expect to live.

Today, when the death distribution is compressed and dominated by the adult peak, average life expectancy at birth is a much more representative statistic than in the past when the average fell between two peaks (infancy and old age). Nevertheless, most people die above the average age, and the most common age at death is almost 90.

It’s a bit more complicated…

So life expectancy is a kind of summary measure of mortality patterns in a population. It allows us to compare mortality trends over time, and between populations. But it is not a measure of the lifespan of a population, or even of the most common age at death.

Calculating life expectancy in real populations is also not quite as straightforward as we have suggested. Take the life expectancy of the English population in the 1960s. This doesn’t actually apply to the cohort of people born in 1960, because to calculate life expectancy for a real cohort we would have to wait until they were all dead in order to know how long they had lived!

So to calculate life expectancy for the people born in 1960, we would take all the deaths that occurred in that year and use these to measure the risk of dying at each age in 1960. We then apply these risks to an imaginary population that was born in 1960 and work out the average age at which they would have died if they had faced these risks at each age. This captures the particular mortality patterns of the year 1960, and is given the technical term ‘period life expectancy’. This is what people usually mean when they refer to life expectancy.

Demographers are, however, also interested in the life expectancy of cohorts of real people. For example, we can follow cohorts with unusual experiences, such as men born in the last years of the 19th century who were of recruitment age in World War I, and compare how they fared compared with other cohorts born before and after them.

William Blake, ‘Songs of Innocence and of Experience’.

Great expectations

The modern rise in life expectancy has provided enormous social and economic benefits. Not only do we live longer, but there has been a massive reduction in uncertainty with respect to both our own lifetimes and the lifetimes of our family and friends.

Further reading

Davenport, R.J. (2021) ‘Patterns of death, 1800 – 2020: Global rates and causes’ in P.N. Stearns (ed.) The Routledge History of Death Since 1800. Routledge.

Wrigley, E.A., R.S. Davies, J.E. Oeppen and R.S. Schofield (1997) English Population History from Family Reconstitution. Cambridge University Press.

Tags: demography, economic history, life expectancy, mortality, old age, social history
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What a big family you have, Grandma!

Thursday, August 1st, 2024

Alice Reid & Jim Oeppen

Looking backwards in time gives a mistaken impression that family sizes in the past were larger than they actually were. This blog explains why this happens, and explores the differences between the picture of the past painted by genealogies and the past as it actually was.

Looking backwards at our families

Alice’s grandmother, Margaret, had six children, of whom five survived to adulthood. She had 14 grandchildren and (so far) 25 great-grandchildren. She also had two sisters, Kathleen and Moira. Moira had two children, four grandchildren and six great grandchildren. Kathleen remained single and childless throughout her life. On average, the three sisters (Margaret, Kathleen and Moira) had 2.7 children apiece.

Kathleen, Moira and Margaret with their mother Agnes (also known as Nan) in 1929. Family photograph, courtesy of Colin Reid.

Of the seven offspring in the next generation who survived to adulthood, five of them came from a family of six, and two from a family of two. If you were to gather them all in a room and ask how many children their mothers had (imagine they were not related and therefore did not worry about whether or not siblings should all answer the question), the answer would be 4.9 children. The view from the children’s point of view is very different, because there are more of Margaret’s children to remember their big family. The fact that Kathleen had no children means that her family size (of zero) cannot be represented in a calculation of mothers’ family size as reported by children.

In the next generation the difference is larger still, with the grandchildren’s point of view suggesting that their grandmothers’ generation had 5.2 children on average, nearly double the real number of 2.7.

Looking back at previous generations of our own families can therefore give an inflated view of how large family sizes were in the past, and can produce distorted impressions of families and family formation.

Alice’s grandmother Margaret (centre), with her surviving children and her husband. Family photograph, courtesy of Colin Reid.

Family history and genealogy

Demography takes a “descendant” viewpoint. The average family size is calculated from the mother’s viewpoint – the 2.7 children in the example above, not the ascendant 5.2. By contrast almost all genealogies are ascendant: i.e. a survivor works backwards, recording the generations in their main line of ascent. (Descendant genealogies select a person in the past and follow their kin forward in time – a future blog will discuss Chinese genealogies, which are usually descendant.) The extent to which a genealogist follows collateral kin in each generation, such as aunts and uncles etc., is variable – depending on the available records and enthusiasm.

King Henry IV of England, in armour and wearing crown, wielding his sword so as to cut Richard II from the Plantagenet family tree (England, 1460 – c. 1470). British Library Harley 7353.

Campop’s work on reconstructing the demography of English families allows us to calculate the ascendant bias in family size from 1550 to 1850 (i.e. the extent to which ascendant genealogies overstate family sizes). The simple formula that links the averages for the ascendant and descendant views has been known for over a century.

To simplify the picture, we start by removing the effect of celibacy (women remaining unmarried) and mortality. Assume that every woman married, and both she and her husband survived to at least her 50th birthday. The descendant average number of children over the period varied between about four and six children, but the ascendant view adds 1.5 to two extra children. This is like comparing the average number of children from Margaret and Moira (four) with the average from their children’s point of view (5.2).

Including women such as Kathleen in the example above, who did not marry or have children increases this bias still further. Celibacy in the past among females surviving to age 50 is thought to have been about 10-15 percent. Adding these women with no descendants to the calculation raises the ascendant bias to about 2.5 children. Similar biases have been found for Basque villages 1800-1969, Brazil 1960-2000, France 1830-1896, the USA 1867-1955, and a variety of late 20th century, high fertility populations.

Genealogy showing the descendants of Adam and Eve (London, 1611). British Library C.35.l.13.(2).

So, women with descendants, who are more likely to appear in genealogies, are not typical of women in general. Their experience should not be used to characterise the experience of the overall population.

Nevertheless, these women with descendants did exist, and it is also worth considering how they managed to fit larger than average numbers of children into their child-bearing histories.

The maximum reproductive span for a woman is 35 years (between the ages of 15 and 50). But women in the British past were aged about 25 when they married for the first time (see blog on marriage), and the typical age at last birth in a non-contracepting population of women surviving to age 50 is 41 years, reducing the average fertile period to 26 years.

Tony Wrigley and colleagues at Campop calculated that average inter-birth intervals were 2.5 years: typical of a population with long breast-feeding. Thus, women in an ascendant genealogy would need an extra 6.25 years of reproduction. They must have married young, lived to 50, or had short birth-intervals (or multiple births), or all three.

Children born to Andrew and Janet Gray, great great grandparents of Agnes (Nan) in the photograph above. Janet’s young age at marriage, survival beyond age 50, and very short birth-intervals enabled her to have 16 singleton births. Image courtesy of Colin Reid.

How do we know?

This knowledge uses ‘family reconstitution’: the reconstruction of families by linking the baptisms, marriages, and burials recorded in parish registers. This process starts with a marriage and locates the baptisms of bride and groom to establish their birth dates and age at marriage. The births of their children are identified, enabling the age of the mother at birth to be calculated. Finally, the deaths of husband and wife are located in the records, yielding age at death.

The same process is undertaken for the marriages of each of the children of the original couple, making inter-generational comparisons possible. Campop created a number of family reconstitutions for a variety of communities across England. These have to be treated very carefully to yield accurate demographic measures, but they are our best source of information about the population of England between the mid-16th and mid-19th centuries.

The bias in ascendant genealogies can be calculated by comparing the average number of children per woman using all women in the population (the descending point of view), with the sibship sizes of those women who had children. In other words, by performing a similar comparison to the example in the first section of this blog.

Further reading

E. A. Wrigley, R.S. Davies, J.E. Oeppen, and R.S. Schofield, English Population History from Family Reconstitution, 1580–1837 (Cambridge University Press, 1997).

Tags: demography, Family history, family size, Family tree, fertility, Genealogies
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Marriage in the Middle Ages

Thursday, July 25th, 2024

Chris Briggs

What do you know about population change in the English Middle Ages (c.1000-c.1500 AD)? Quite possibly, you have an inkling that the couple of centuries or so following the arrival of the Normans in 1066 were an era of steady growth in numbers. Almost certainly you know that that growth came to a juddering halt in the middle of the 14th century with the Black Death of 1348-9, and further outbreaks of plague and epidemic disease in the decades that followed.

Agricultural labourers, 15th century. Source: Wikimedia.

But what about the mechanisms of change: patterns of births (fertility), deaths (mortality), and migration? These are the central concerns of demographers, but they become murky matters when we try to go back before 1500. The limitations of the medieval sources make it hard to speak with confidence on some of the most important questions about demographic behaviour in this early period.

Yet substantial progress has been made over the last 60 years or so, thanks in no small part to work done within Campop. An especially significant contribution has been made by the Group’s former Director, Professor Richard Smith, and several of his former graduate students, most notably L.R. Poos and P.J.P. Goldberg.

This body of research suggests, in essence, that medieval marriage, fertility, and household and family structure was much more like that of later periods, and indeed more like that of the modern world, than was previously thought.

Early modern research

As described in a previous blog, the average age at first marriage was relatively high for both men and women in the British past, and the proportion of people who never married was also relatively high, with between 15 and 20 percent of women remaining unmarried in their 40s. This pattern – known as the European Marriage Pattern (EMP) – has been traced back into the 17th century.

Campop’s work on parish registers of baptisms, marriages and burials, which survive for the period from 1538, showed how T.R. Malthus’s ‘preventive check’ operated in early modern England. Marriage, which was not universal, was delayed until economic opportunity allowed, which (given most childbearing occurred within marriage) in turn shaped population trends.

Campop’s research also demonstrated the prevalence of small, nuclear households in the past, as opposed to complex multigenerational ones; the ubiquity of the institution of servanthood, which saw unmarried young people leave their homes to live and work with their employers and accumulate savings; and the general tendency for the establishment of a new household upon marriage.

Wedding of Louis X of France and Clemance Hongrie (1315). Source: Wikimedia.

Contemplating these findings, scholars interested in earlier periods asked: how far could similar structures be traced in the era before parish registers? Was medieval demographic behaviour fundamentally different, as had often been assumed – or could the EMP be traced back into the Middle Ages?

The questions were clear. Finding the sources with which to answer them systematically for the period before parish registers was a different matter.

Very challenging sources

Quite often, medieval records say a lot about just one or two places, and require us to try to work out how typical or otherwise they may be of an entire region or country. The inventories of male serfs (unfree tenants) and their offspring produced in the 1260s by Spalding Priory (Lincolnshire) for three of their nearby manors are a good example of this. These lists reveal the priory’s desire to track the valuable ‘human capital’ on its estate. They tell us about the whereabouts and occupations of many of the children of serfs, male and female. They also indicate their marital status, and so can be used, for instance, to estimate the proportions married.

Court Roll for the Court of Eusace Grenville in Wotten Underwood, Buckinghamshire (1431). Source: Wikipedia.

Another source that has been prominent in medieval demographic studies is the manorial court roll. This is the record of the manor court, a legal tribunal held by a landlord for his tenants and other local people. In the fullest and most complete series, such as those of Redgrave and Rickinghall (Suffolk) used by Richard Smith, the names of hundreds of peasants appear. There are dozens of data points for the best recorded individuals.

Of course, not everyone in a community appears in the court roll, and women are under-recorded. Despite this, attempts have been made to produce a complete ‘reconstitution’ of the population of a manor, along the lines of those undertaken for the early modern era using parish registers. These have then been used to calculate a variety of demographic measures. Court rolls also often include records of the ‘merchet’ fine, which serfs had to pay for permission to marry. This has obvious value for studies of marriage and fertility.

Court rolls tell us about change over time, unlike our third source, the returns to the three poll taxes of 1377, 1379, and 1380-81. These essentially function as a snapshot of conditions in post– Black Death England.

The poll tax is famous as the trigger for the Peasants’ Revolt of 1381. Yet for medieval demographic historians, its richly detailed records are most prized for the information they hold on taxpayers, their marital and familial relationships, and their occupations. The three poll taxes were payable by all lay people, male and female. They basically excluded only children and the truly indigent. The best returns are thus somewhat less affected by the problems of omission that bedevil most medieval sources.

Findings

All these sources have been used by demographic historians for purposes that were never originally intended. To deploy them effectively requires the researcher to combine the archival skills of the medieval historian, with the technical know-how of the demographer. Not surprisingly, therefore, work on these materials has been replete with methodological debate.

Any simplified summary of ‘findings’ comes with a health warning, since in medieval demographic history, the uncertainties and margins for error are higher than usual. Logic, inference, and comparison with better documented periods and places are as important as hard evidence.

That said, there exists a substantial body of work produced by Campop that has helped to push back the evidence for the European Marriage Pattern into the pre-1500 period.

Detail of an historiated initial ‘S’ of a man placing a ring on a woman’s finger. 14th century. British Library Royal MS 6 E VI, fol. 104. Source: Wikimedia.

For instance, work by Smith and others on the 1377 poll tax revealed that around 60 percent of females were married. Similar proportions were found in analysis of the Spalding serf registers of around a century earlier. These figures are close to the proportions of persons identified as married in studies of household listings of the 17th century.

A good deal of this medieval demographic work also focused on servants, both male and female. Their numerical presence in the 14th–century poll tax returns was again like that found in the early modern evidence. In 1377, for instance, some 20 percent of households in the county of Rutland possessed servants.

The picture that emerged from Campop’s work was more robust for the period after the watershed of the Black Death, thanks largely to the availability of the poll taxes. The period before 1348 is generally more obscure. Smith in particular expressed serious doubts about the likelihood of being ever being able to calculate crucial measures of fertility, especially marriage ages. It was argued that there were simply too many unknowns affecting the merchet fines contained in the manorial court rolls.

Nonetheless, by the end of the 1980s, a coherent case had emerged for the existence of the European Marriage Pattern and its related household structures in England before 1500, and possibly before 1300.

Lying behind all this work was the idea of a demographic regime in which marriage, reproduction and the formation of new households was shaped by economic opportunities – including work opportunities for women – in a way that differed from southern and eastern regions of Europe. It had potentially huge implications for understanding long-term patterns of economic growth.

Not everyone agreed, of course. Zvi Razi, in a ground-breaking 1980 study of court rolls, presented a different picture of medieval English demography. His ‘reconstitution’ of the population of Halesowen in the west midlands revealed a ‘high pressure’ demographic regime of high fertility and mortality, comparatively early marriage, and large and complex households. Debate ensued about how far Razi’s findings showed genuine regional differences, as opposed to flawed assumptions about the capacity of his court rolls to support demographic analysis.

The formal part of the medieval marriage ceremony often took place in a church porch like this late fifteenth-century example at Aylsham, Norfolk. Source: Wikimedia.

Recent work

The pioneering studies described above were mostly undertaken 30 and more years ago. The pace of fertility-focused research in medieval demography has slowed since the 1990s, both in Campop and elsewhere.

This is partly the result of the abovementioned scarcity and difficulties of the surviving sources, and the technical demands on the researcher. Nonetheless, some important work has come out recently, undertaken not within Campop, but inspired by its approach and findings.

This includes Judith Bennett’s study of the EMP and its origins based on a reappraisal of the Spalding Priory registers, and an investigation of the relationship between fertility and living standards by Kelly and Ó Gráda. In both cases Campop’s arguments about the early existence of the EMP and the importance of the preventive check receive support.

Despite the challenges, exciting questions and opportunities in this field remain.

And finally: what about mortality…?

Readers may be puzzled as to why a blog on medieval population history has said so little about plague, disease, and early death. The answer is partly that the aim here has been to emphasize the importance and creativity of work on marriage and fertility, even if it is so frustratingly difficult to study.

Medieval deaths are certainly much better recorded than marriages and births. And plenty of scholars would argue that it is changes on the mortality side that are key to understanding medieval population dynamics. But that, as they say, is another story – or another blog.

Further reading

Judith M. Bennett, ‘Wretched girls, wretched boys and the European Marriage Pattern in England (c.1250-1350)’, Continuity and Change, 34 (2019), 315-47.

P.J.P. Goldberg, Medieval England: a social history 1250-1550 (2004), chapter 6.

Andrew Hinde, England’s population. A history since the Domesday survey (2003), Part I.

Morgan Kelly and Cormac Ó Gráda, ‘The preventive check in medieval and preindustrial England’, Journal of Economic History, 72 (2012), 1015-35.

L.R. Poos, A rural society after the Black Death: Essex 1350-1525 (1991).

Richard Smith, ‘Some emerging issues in the demography of medieval England and prospects for their future investigation’, Local Population Studies, 100 (2018), 13-24.

Tags: demography, marriage, medieval, medieval history, middle ages, poll tax, social history
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Why was high family size in the British past so low?

Thursday, July 18th, 2024

Alice Reid

Today most of the world’s population lives in places where, on average, women have fewer than two children over their lifetime, but this level of childbearing is a relatively recent phenomenon.

Before the demographic transition – the change from high and variable birth and death rates to low birth and death rates (usually taken as 1870-1930 in the UK) – women had higher numbers of children, and it is generally accepted that they did not deliberately restrict the numbers of children they had.

Given that before the demographic transition in other parts of the world, women had an average of around six or seven children, it is surprising that British women have never had more than five children, on average, over the course of their lifetime.

Sir Thomas Remington of Lund in the East Riding of the County of York, Knight, Dame Hannah his wife, daughter of Sir William Gee of Bishop Burton, Knight, and their issue. 1647. Image courtesy of York Museums Trust. Public Domain.

How high is high fertility?

Theoretically a woman could fit in over 30 children during a roughly 30-year reproductive period between menarche and menopause. Although there are instances of individual women having between 20 and 30 children – for example Sir Thomas and Lady Remmington of Lund in Yorkshire, illustrated in the image above with their 20 children – this is very unusual, and there are very few societies, past or present, where the average number of children per woman exceeds eight. The highest documented fertility of any community is associated with the Hutterites, a small North American religious sect, where in the mid-20th century women had an average of 8.9 children.

There are a number of physiological and behavioural factors which can reduce the number of children born to each woman. These include miscarriage and stillbirth (which are generally not included in calculations of birth rates); the fact that some women lose the ability to conceive earlier than average through birth complications, disease, or early menopause; the fact that new mothers generally do not ovulate for some months after the birth of a child, and the longer and more intensively they breastfeed, the longer it takes for ovulation to return; and the fact that if the timing of sexual intercourse is random, couples might miss their fertile window in some months.

These factors together tend to reduce the number of children an average woman might have even if she was in a sexual relationship throughout her childbearing years, and not using any form of contraception, to around eight children.

Marriage patterns reduced fertility in historic Britain

Time spent outside sexual relationships reduces fertility still further in populations where no or few couples were trying to prevent conception, and this is the major factor reducing fertility levels in historic Britain. Before the demographic transition, when mortality was still relatively high, the death of either a woman or her husband would curtail her opportunity to have children.

More important for reducing numbers of children born in England and Wales to levels lower than many other parts of the world, however, were late ages at marriage and substantial proportions of women who never married.

Although sexual intercourse outside marriage did happen in the British past, most children were born to married couples until well into the last quarter of the 20th century (watch out for future blogs on this topic).

Photo from E. W. Hope, Report on the physical welfare of mothers and children (Liverpool, The Carnegie United Kingdom Trust, 1917), volume 1.

Both late ages at marriage and a substantial portion of the population who never married have the ability to considerably reduce the number of children born to a woman. We saw in a previous blog that the age of first marriage in England ranged between 24 and 26 until the post-2WW marriage boom, when women married younger than ever before. Given that the chance of conceiving reduces with age, particularly beyond the age of 30 or so, relatively late age at marriage means that women spent many of the most fertile years of their life unmarried and therefore with little chance of becoming pregnant.

In addition, a relatively high percentage of women (on average 13.5 percent) remained unmarried throughout their childbearing lives. When age at marriage was higher, more women never married at all, with as many of 27 percent of women born in the mid–17th century remaining single at age 50. There were very few time periods when less than five percent of women remained unmarried, and this occurred when age at marriage was low, for example among women born in the mid– 18th century.

In contrast in most South Asian countries (e.g. India, Bangladesh, Nepal, Pakistan) until the 1980s women married before age 20 and only one or two percent remained unmarried at age 50. These differences in marriage patterns are the main reason for considerably higher average numbers of children per woman before the demographic transition in South Asia than in Britain (and other parts of North-West Europe where marriage patterns were similar).

Fertility levels and population growth

Populations grow when there are more births than deaths (not counting the influence of migration). The relationship between fertility in terms of the number of children per woman and the number of births per 1,000 people is not a simple one, as it also depends on the age structure of the population. High fertility in the recent past can produce large cohorts of women in the childbearing ages, and these can contribute to a high number of births in relation to deaths even if the number of children each woman has is low.

Nevertheless, there is a widely used measure – the ‘replacement rate’ – that indicates the number of children a woman needs to have to ‘replace herself’ and therefore keep the population from either growing or shrinking. Globally, today, this number is around 2.1; just over two because although around half of all children born are female, slightly more children born are male, and also because not all children reach adulthood.

In the past, however, this number was considerably higher, principally because mortality was higher, so more children needed to be born in order to ensure that one female born survived to childbearing age. Therefore although women had between four and five children each in Britain, this did not mean the population grew rapidly. For most of the pre-industrial period, the British population grew slowly, if at all, because fertility and mortality were more or less in balance.

Unknown artist, Five Children of the Pigott Family (1740). Courtesy York Museums Trust.

Moderate fertility as part of a low-pressure regime

In other pre-demographic transition populations with low population growth, higher fertility levels were accompanied by higher mortality levels. When Tony Wrigley and Roger Schofield at Campop produced the long-run series of fertility and mortality for England, they suggested that this was part of a ‘low–pressure’ demographic regime. Such a regime was characterised by moderate levels of both fertility and mortality, with low fertility achieved through marriage as described above. In contrast, ‘high–pressure’ regimes were characterised by higher levels of both fertility and mortality.

How do we know?

Fertility, or birth rates, can be measured in a number of different ways. The simplest measure is the crude birth rate, the number of births in the population in a year, per 1000 people. This is easy to calculate, particularly since the state started to register births (1837 in England and Wales and 1855 in Scotland).

However, this blog has talked mainly about a different measure, the total fertility rate, which is defined as the number of children each woman could expect to have over the course of her childbearing life. We can measure this for actual cohorts of women (women born in particular years) by waiting until they reach the age of around 50, when further childbearing is unlikely, and counting the numbers of their children.

However, this means it is necessary to wait until a cohort has reached the age of 50, as it is not possible to derive this information from birth certificates. Instead most total fertility rates are ‘period’ rates, calculated by calculating fertility rates for age groups of women (numbers of children born to women in a particular age group and dividing by the number of women) and assuming that women go through their childbearing life experiencing those rates in sequence.

Period total fertility rates can be calculated for England and Wales since 1938, when the age of the mother started to be recorded on birth certificates. Between 1851 and 1938 they have to be estimated. Here we have estimated them from census data by working out the age at childbirth of women living with their children and making various adjustments for children who died or were not living with their mother (this technique is called the ‘own children method’).

For the pre-industrial period, total fertility can be estimated from parish registers which recorded baptisms, marriages and burials. Linking the births to different women, and to her own baptism, allows age–specific fertility rates to be constructed, and the numbers of births to women across their lives can be counted.

Further reading

Bongaarts, J. (1975) Why High Birth Rates Are So Low. Population and Development Review, 1(2): 289-296.

Wrigley, E.A. and R.S. Schofield (1989) The Population History of England 1541-1871. CUP.

Tags: Demographic transition, demography, Family history, family size, fertility, marriage
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What was the size of the English population before the first census in 1801 – and how do we know?

Thursday, July 11th, 2024

Jim Oeppen

Campop’s estimated series of population totals for England from 1541 to 1871 are the longest and most detailed available for any country. The associated age-structures have been used to provide summary measures of fertility and mortality, such as replacement rates and life expectancy. The opportunity they present for extending per capita analysis into the past means that they have become a standard reference for historical demography and economic history, and have been cited in over 1,500 academic publications.

Why do we need to calculate population size?

Expressing data “per capita” is an essential part of how we understand social and economic statistics today, but this kind of calculation relies on knowing the population total. Before 1860, the term “per capita” was extremely rare. (Try typing “per capita” or “per person” into Google Books Ngram Viewer.)

This is not surprising when you consider that there was no census of England and Wales before 1801, and age-breakdowns only began in 1821. Part of the rationale for taking the first census was that politicians couldn’t decide whether the population was increasing or decreasing. It is surprising that they didn’t know, as we now know that the population was increasing very rapidly!

So how do we calculate historical population size without a census?

In the absence of census data before 1801, Campop’s population estimates are derived from annual counts of baptisms and burials. After adjustment, these can be used as proxies for births and deaths. Official registration of births, deaths, and marriages began in 1837, but the established Church in England had been registering baptisms, marriages, and burials since 1538.

Ascension parish burial ground Cambridge. Source: Wikimedia.

Campop encouraged their army of volunteers to find local parish registers and count the events in each month. The initial aim was not to estimate the population, but to find registers without gaps that might be suitable for Family Reconstitution (a technique for the detailed analysis of family demography).

However, once the counts started coming in, it became apparent that they were an important resource in their own right. It was decided that they could be used as a sample that could be inflated to represent national estimates of births, marriages and deaths.

A total of 404 parishes were identified that satisfied a suite of criteria for accuracy and completeness. These represent a four percent sample of the 10,000 ancient English parishes. They provide 3.7 million baptisms, marriages, and burials in monthly totals.

Problems and adjustments

These 404 parishes were not a random sample. The biggest issues were that large parishes were over-represented; there were no London parishes; and the series started and stopped at different dates. For example, between 1662 and 1811 all 404 parishes were in observation, but in earlier and later years the number declined.

Going from baptisms and burials to “national” totals of births and deaths involved a long series of adjustments. These included inflating the births to allow for deaths before baptism; and adding under-counted non-Conformist births and events for London. Finally, the sample was re-weighted so that the large parishes lost their dominance in the counts.

Validating the estimation method

Sweden has records of deaths by age, censuses, and life tables from 1751. It also has high levels of net-outmigration in the 19th century. We can pretend we don’t know about the censuses, and only use the totals of births and deaths with the 1901 census as targets. The estimation method was able to satisfactorily match the observed censuses from 1751 onwards, and the net-migration rates.

The estimated values for English life expectancy derived from totals of births and deaths are remarkably consistent with those derived from subsequent research on individual life histories in Campop’s English Family Reconstitution studies.

Figure 1 (below) shows Campop’s estimates of the population of England from 1536 to 1796, together with the decadal Census counts for England from 1801. The period from 1541 to 1651 exhibits rapid exponential growth, followed by a period of stagnation, before exponential growth returns in the 19th century, but with a slower rate after 1901. The population doubling time was about a century in the first growth period, but became even more rapid in the 19th century, shortening to 50 years.

Findings

Using this information, Campop members were able to make a series of discoveries about populations in the past, including:

Dependency ratio

A historical definition of the working age population is between the ages of 15 and 60, with those older and younger regarded as ‘dependent’. Although there have been changes as the population grew and stagnated, and these changes had important social and economic consequences, the Dependency Ratio hovered around 70 dependents per 100 providers from 1551 to 2021. This stability masks an important transition. Before 1900 there were five children for every elderly dependent. The 20th century saw this fall to one child for each elderly person.

Georgios Iakovidis, The Favourite (1890). Source: Wikimedia

Net migration

The net-migration estimates show consistent out-migration at the low rate of about one to two persons per thousand per annum. It is likely that in-migrants, particularly from Scotland, Ireland and Wales, almost balanced English emigration to the rest of the world.

Fertility and life expectancy

The pre-census population estimates can be used to derive demographic measures of fertility and survival from 1551 to 1841. For example, we found that women who survived to age 50 only had about five births on average, which is very different from typical expectations about the past – look out for a blog post about this next week!

Life-expectancy at birth derived from these populations was generally between 30 and 40 years, but around 20-25% of people were aged 40+. If you wonder how this can be possible, it will be discussed in the forthcoming blog “Three Score and Ten”.

Population dynamics

From these estimates, we can see that the impact of epidemics on England’s population has been minor and transitory. From 1541 to 1851, changes in fertility were more important than changes in survival in determining population growth. The importance of age at marriage as a factor influencing fertility is discussed in another of today’s blogs…

Further reading

HMD. Human Mortality Database. Max Planck Institute for Demographic Research (Germany), University of California, Berkeley (USA), and French Institute for Demographic Studies (France). Available at www.mortality.org

R. D. Lee, “Estimating Series of Vital Rates and Age Structures from Baptisms and Burials: A New Technique with Applications to Pre-industrial England,” Population Studies, 28 (1974), pp. 495-512.

E. A. Wrigley and R. S. Schofield, The Population History of England 1541-1871: a reconstruction (Cambridge University Press, 1981).

E. A. Wrigley, R. S. Davies, J. E. Oeppen, and R. S. Schofield, English Population History from Family Reconstitution: 1580-1837 (Cambridge University Press, 1997).

Tags: census, demography, Family history, parish registers, population size
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Top of the Campops: 60 things you didn't know about family, marriage, work, and death since the middle ages

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