Friday, February 15, 2008

Nasty Brutish and Short I

Nasty Brutish and Short

The 21st century will doubtless bear witness to a great many new and strange phenomena, but somewhere high up on the list of things which are going to define the coming century will surely be the fact that most countries experienced a substantial and sustained ageing in their populations as the century progressed. This phenomenon of population ageing, which has now become something of a commonplace for us, is in fact the result of a twofold process, a general decline in birth rates, and a generalised and substantial increase in the levels of life expectancy.

In the developed world birth rates have long been falling, and are now either hovering around ( one or two countries like the United States and Ireland) or significantly below (the rest of the OECD member states) replacement level. Since there is no consensually agreed theory among demographers which explains why fertility rates have fallen so low the future trajectory of fertility is hard to foresee, but in the immediate future it is clear that for many countries below replacement levels of fertility are likely to remain the norm, and the big question - the billion dollar one in fertility theory terms - is really 'just how low can you go'?

Side by side with this most developing countries are, and will continue for some time to be, in the process of seeing their fertility levels fall steadily (and even dramatically) from TFRs which are initially in the high to moderate band, first to replacement, then to below replacement, and finally to lowest-low fertility and beyond. The case of Iran is instructive here. Having dropped from around 5 to just under 3 between 1989 and 1996, Iran's total fertility rate has continued to decline rapidly, and in the early years of this century dropped below replacement level. data from results from the 2000 Demographic and Health Survey (DHS) for Iran revealed a decline of 32 percent in the TFR between 1996 and 2000, from nearly 3 to around 2 children per woman. The data also shows that reduced fertility is not simply an urban phenomenon but is occurring throughout the country, with some of the most dramatic declines being in the rural areas, where the 1996-2000 decline was some 31% when compared with only an 18% decline in the urban areas (Abbasi-Shavazi, 2002). Data from the Italian statistical agency ISTAT reveal a similar picture with TFRs in the North rising steadily from 1.05 in 1995 to 1.34 in 2005 while in some rural regions fertility fell to very low levels ( Sardinia 1.07, and Molise and Basilicata 1.14, see ISTAT 2006).. Data for East Germany reveal a similar pattern, in that the TFR rapidly converged towards and then went below the already low level of the former Federal Republic. Thus if convergence is taking place (see Wilson, 2001) it is both between and within countries and towards intitially lowest-low fevels of TFR.

At the time of writing some 71 countries (or 43% of the global population) have fertility rates which are in the 2.1 to 5.0 TFR band. These countries are classified by the United Nations as 'intermediate fertility' ones (UN, 2002). Essentially all those countries where TFRs have already fallen below 5-0 may conveniently be described as having initiated their demographic transition, and as such these countries are experiencing steady and sustained fertility declines. It is reasonable to expect that between now and 2050 they will all enter the below replacement fertility group, with the vast majority entering sooner rather than later. As and when they do so they will steadily swell the ranks of the 44 countries who already 'enjoy' this status.

The consequences of such generalised low fertility are not hard to imagine: populations will gradually start to decline and in an increasing number of countries. At the same time our populations will become older, and even a quick glance at any of our garden variety news sources will nowadays normally suffice to find some reference or other to long-term population projections which show truly daunting ageing figures. If, for example, fertility rates in the developed world remain, as they are today, well below replacement, and if we continue to experience improvements in life expectancy at the current rate, then half the population of today's industrialised countries is projected to be over 60 by the time we enter the last quarter of the 21st century. Of course just how 'old' 60 will actually be by the time we get there is an issue in and of itself, and one which forms a significant part of the 'meaty content' of the present ageing debate.

At the same time many developing countries, such as, for example, China, may well find themselves ageing in an especially dramatic fashion, since fertility rates in the third world have been falling very rapidly (UN, 2002) and longevity rates are also rising equally dramatically. So, if the current distribution between working and retirement ages is maintained, in less than two decades China will find itself facing an old-age dependency burden similar to the one which can be found in the older Western European countries today.

The 'ageing phenomenon' itself, of course, willl come as no surprise at all to anyone who has a smattering of knowledge about standard demographic theory, since progressive ageing could arguably be considered to be one of the 'stylised facts' associated with the process which has come to be known as the demographic transition. Now the term demographic transition has normally been used to describe the transition from a demographic regime based on high birth rates, high infant and child mortality rates and low life expectancy to a regime more typified by falling birth, infant and child mortality rates, together with steadily increasing life expectancy. This process has often been thought to occur as a core part of the economic development and modernisation process which carries a country from the condition of being a pre-industrial society to one of being an industrial and then a post-industrial one (Easterlin, 1995, 1983 Caldwell, 1982).

What Is The Demographic Transition?

From the end of World War II and until at least the 1980s, there was probably no research issue that was either mentioned more frequently or debated more passionately in demographic literature than the theories and explanations adavnced in relation to the phenomenon which has become known as the demographic transition.

Transition theory has, right from the start, been characterised by a penchant for a phasal typology, and the original formulation of the theory was no exception to this rule, being presented as it was in terms of a three stage demographic evolution from a regime of high birth and death rates - "a high balance" - to one of low birth and death rates - "a low balance". An intermediate stage of high rates of natural population increase was thought to result from a tendency towards faster declines in death rates than in birth rates. Early pioneers of the theory like Warren Thompson and Frank Notestein, in addition to presenting the basic classification system, also suggested a list of major correlates and causes of fertility decline. These included decreased infant and child mortality, the spread of urbanization, increased costs of raising children, rising parental aspirations, increases in literacy, rises in women's status, a rise in individualism, a decline in religiosity and changes in other cultural factors. Many of these factors have often been included under that wide umbrella which has become known as the modernization processes.

According to the original version of the standard theory, after years of - more or less - homeostatic population drift (often termed the 'Malthusian era'), the start of the transition itself is normally thought to be marked by a sharp and sustained decline in mortality, and in particular by a decline in infant and child mortality. This mortality decline in and of itself produces a large and significant drop in the median age of the society concerned. After this it is, in one sense, up-hill all the way, since normally societies tend to embark on a continuing ageing process, an ageing process which has to date no known end-point. In this sense both the fertility decline associated with the initial or 'first' transition and the more recent one which sees the arrival of below replacement fertility - a process which some have ventured to call the second demographic transition - are intimately related, since the underlying 'driving factors' are undoubedly the same and the whole process is, in its core, an ageing one.

This alone should alert us to at least one difficulty: is it really adviseable to use the expression 'ageing society' in relation to our contemporary developed societies, since if collective ageing is associated with declining fertility and increasing life expectancy, then our societies have long been ageing ones, as indeed they will continue so to be for as far ahead as we can see.

Are There Really Two (Or Should That Be Three) Transitions?

As has been suggested there are those who in addition to breaking the demographic transition down into stages would also break it down into 'transitions'. Insofar as some theorists have gone on to use the expression 'second transition' (Lesthaeghe, 1995, Van de Kaa, 1987) they have normally done so in order to break the entire fertility transition down into two component parts, one which sees fertility decline from its earlier 'higher' pre-modern steady state to the modern, industrial-age near-replacement level, and a second, posterior, transition during which fertility drops from replacement level to one which is substantially below replacement (and in many cases falling as far as what some - Kohler et al, 2002 - have termed 'lowest-low fertility' which they define as lying in the sub-1.3 Total Fertility Rate range). As has previously been argued, there is no sound theoretical or empirical basis to justify making such a radical distinction between a first and a second transition, nonetheless since this terminology is widely used, it will continue to be applied here as a convenient shorthand for describing that package of social and other life course changes which are conventionally associated with the arrival of below replacement fertility.

Stylised Facts Concerning the Modern Demographic Transition

1/. As has been said the key differences between the two 'transitions' (the early pre-industrial transition and the later post-industrial one) is that while in the first case the fertility decline was accompanied by a sharp and continuing drop in infant and child mortality, in the second one it is old-age mortality which declines alongside the continuing fertility decline and it is the life-expectancy of the older-old which rises. This process is sometimes described as the rectangularisation of mortality in reference to the way in which the age-related mortality curve changes during the different stages of the transition, moving as it does from a U shape towards a rectangle as mortality gets gradually compressed at both extremes. The combined impact of the two phases of the transition then is that - after an initial "mortality shock" - all societies enter a process of seemingly continuous ageing. One noteable contemporary consequence of this is the fact that today there are only 18 countries - themselves considered to 'demographic outliers' by the United Nations (and identified as such in the 2005 edition of their Human Development Report) - which are not actually ageing.

So this is the first stylised fact: the demographic transition is a transition from a society with a relatively stationary age structure, and relatively static life expectancy, to one with a gradual and continuous increase in life expectancy and a steadily rising median age. In short, the transitional/post-transition society is an ageing one.

2/. In global terms it is undoubtedly true to say that the twentieth century was the century of life expectancy, since during its course average life expectancy at birth more than doubled - rising from an average of around 30 in 1900 to some 65 years by the end of the century (Riley, 2001). It may well be possible to say the same of the century to come too, since if present trends continue the planetary average life expectancy is projected to further rise to around 81 by the end of the 21st century (Lee, 2003). There is still no consensually agreed explanation for why life expectancy has been increasing in this way. Indeed there is some dispute as to whether in some cases it will now actually begin to decline (the case of obesity in the United States would be but one well-known example of a counter case, declining male life expectancy in Russia would be another, and the Aids epidemic in Africa another (Olshansky et al, 2005, Brainerd and Cutler, 2004, Pelletier, 2004). At the same time there is still no agreement among scholars about whether - as for example James Fries believed (Fries, 1980) - human lifespans have a more or less fixed upper limit or whether a phenomenon known as 'negative senesence' may not be at work (Vaupel et al, 2004). The key question is, as the cohorts which have had heavy disease loads and nutritional deficiencies in their early years pass through their life courses, and life expectancy pushes up towards the previous 'higher limits' whether subsequent cohorts will still exhibit the same upward trend in expectancies. Such uncertaintly not withstanding, and amidst so many potential areas of dispute, one factor does seem to be evident:: the process of increasing life expectancy has been closely associated with increased levels of education and with growing health awareness. In particular almost all studies of the topic highlight the fact that life expectancy and level of education have a strong positive correlation. So significant has the relation between increased life expectancy, increased education and economic growth been across in almost all countries that have experienced a fertility decline, an industrial revolution, and a modern process of economic growth that Columbia University economist Xavier Sali i Martin concluded a recent review of the last 15 years of new growth research with the conclusion that "life expectancy is one of the variables most robustly correlated with growth" (Sali i Martin, 2002). Since as Sam Preston has demonstrated life expectancy is itself correlated with education levels, it is possible that we have here in outline form one important part of the transition transmission mechansism (Preston, 1996)..

Equally the twenty-first century is almost certainly going to be the century when low fertility (meaning by this below replacement fertility) becomes the global norm since as it runs its course the vast majority of our planets population will enter below replacement level fertility regimes. In this sense something important is happening as we are almost certainly fast approaching a turning point in terms of population dynamics, and it is highly probable that global population will peak later in the century, possibly during the last quarter century (UN, 2002).

This then is the the second 'stylised fact' of the transition: the post-transition society has two core characteristics, declining fertility and increasing life-expectency. In fact it is perfectly possible that these two components are themselves interconnected, and this is a possibility which will be extensively explored in the subsequent sections of this book.

3/. The third 'stylised fact' is that while all societies age during the transition, not all age at an equal rate. Differences between societies are evident in terms of the relative rates of fertility decline and the relative rates of increase in life expectancy. Both of these differ substantially from one society to another, and clarifying the factors which lie behind such differences in transition rates and timing is undoubtedly one of the outstanding challenges still facing demographic research.

4/. Another trend has been that those societies who entered the transition earlier generally passed through it at a slower pace, while those who have started their transition later - and in particular in the most recent cases of the drop below replacement fertility - it seems that the process has accelerated considerably (UN, 2002). Indeed it is normally true to say that the later the entrant, the more rapid the subsequent fertility decline and the shorter the generational timescale required to reach the higher life expectancies associated with economic development would seem to be an increasingly valid generalisation. There is possibly an acceleration principle in operation here.

5/. A closer examination of declining fertility quickly brings us face to face with what might be called the fifth stylised fact: about the transition and this is that the fertility transition is normally accompanied by (and in fact often the result of) a steady and continuous increase in woman's mean age at first birth (WMAFB).This state of affairs was often less than evident, since at certain key points in the transition WMAFBs have fallen rather than rising (in England in the late eigtheenth century, during the industrial age following what became known as the second industrial revolution, and more recently after WWII in the context of the so-called 'baby boom' phenomenon). Indeed in the 'second', below replacement, transition this lowering of the MAFB process plays a predominant role, with changes in final parities having a relatively secondary overall importance (Sobotka, 2004). Developed fertility regimes now seem to be characterised by steadily rising MAFBs, and there seems little realistic likelihood that this situation will reverse.

6/ Finally, the increase in WMAFB is normally closely correlated with a steady rise in female education levels, female participation rates in employment and in the number of years of education and training required before entering first employment.. (Elaborate).

Was Life Really So Nasty and Brutish Before the Transition?

Safely armed with the above list of basic 'facts' we are now perhaps in a better position to understand some of the principal characteristics of the demographic transition process itself, but before moving forward to explore this, it may be worth pausing to think a little about life before the transition, life in the pre-transitional society, what was that actually like? How can it best be defined and understood? Was it really, as some have suggested, 'nasty brutish and short'? And if it was so, was this always and everywhere? This question is certainly worth asking ourselves since according to what seems (among economists at least) to be the most widely accepted version our pre-transition reality:

"Until the early 18th century, global population size was relatively static and the lives of the vast majority of people were nasty, brutish, and short.” (Bloom et al 2002).

Or, in the words of Berkeley demographer Ronald Lee (Lee, 2003):

"Before the start of the demographic transition, life was short, births were many, growth was slow and the population was young."

At this point, of course, all the roads lead us back to the work of the very Reverend Thomas Malthus for whom, it will be recalled, slow population growth was no accident. For Malthus population in the long run was held in relatively stable equilibrium with a slowly growing economy by a combination of what he termed 'positive' and 'preventive' checks.

The basis of Malthus's argument is straightforward enough, and really only depends on two fairly simple postulates. The first of these is the evident reality that humans need to eat and thus need food, the production of which in historical societies increases only slowly with time. And secondly there is the idea that 'nature itself' has ordained a passion between the sexes which remains constant through time. This latter 'instinctive urge' should, Malthus thought, lead to a steady stream of children coming continuously online. Since our resource supply can only be improved gradually not all of these children can be be maintained, and herein lies the source of what he termed the positive check.

Now Malthus himself has often been read as suggesting that populations are maintained virtually on the edge of starvation. In fact this is not necessarily the case, either according to the Malthus theory, or in reality. In hunter gatherer societies, for example, it has been estimated that violent deaths, often in warfare, accounted for around 30% of male adult mortality (Coleman 1986). Thus Malthus' mechanism might rather work due to the fact that the increase in population creates additional mortality issues, and one of these is the fact that the increase leads people to take more risks, such as moving farther afield to hunt etc, and in this way the level of 'population attrition' might well turn out to be greater.

Also there is the fact that Malthus himself believed that the greatest mortality problem associated with a limited food supply occured as a result of the fact that those who are under-nourished are more likely to die of infection, especially during epidemics. With more young to fend for, and less nutrition per capita, infants and young children are surely more vulnerable to even the simplest of health insults. This view is really not that far from the opinions of most modern epidemiological theorists and a brief look at the data for death from diahorrea in some third world countries today lamentably still offers a clear and simple illustration of the continuing operation of the process Malthus described.

We don't then need to read Malthus over-simplistically and indeed in some senses his argument here is surprisingly modern: as the Caldwells note, his argument on child nutrition and susceptibility to infection is not at all incompatible with the 20th ventury work of writers like Thomas McKeown and Robert Fogel (Caldwell, and Caldwell, 2003). As I have said Malthus's positive checks were really what we would nowadays call resource constraints: increasing population would inevitably find itself pushing against an agricultural output which was simply unable to keep pace (in a non Boserupian technological environment), and the resulting "misery" and undernourishment leads to a mortality rise which serves, in the long run, to counterbalance the increase itself.

Malthus's preventive checks, on the other hand, were not natural but social in character. They were constituted by socially evolved mechanisms designed to constrain fertility such as, for example, delayed marriage, protracted lactation or pre-modern forms of contraception (although it is important to note that Malthus himself was completely unaware of the possible importance of factors like lactation, or the fact that our reproductive biology may contain its own feedback components which are internalised in what has now become known as 'natural fertility' control: see Henry,1961 Ellison, 2001).

In the case of pre-industrial Europe, as well as in pre-modern foraging societies, Malthus was, in a certain sense, right: population was normally held in a kind of weak equilibrium with its resource environment via a combination of positive and preventive checks. In saying this we need to be cautious in just how we interpret the expression 'weak equilibrium. Robert Fogel, in his Nobel acceptance speech (Fogel, 1993) makes just this point:

"(My) analysis.....points to the misleading nature of the concept of subsistence as Malthus originally used it and as it is still widely used today. Subsistence is not located at the edge of a nutritional cliff, beyond which lies demographic disaster. The evidence outlined in (this) paper implies that rather than one level of subsistence, there are numerous levels at which a population and a food supply can be in equilibrium, in the sense that they can be indefinitely sustained. However, some levels will have smaller people and higher “normal” (non-crisis) mortality than others".

In other words according to the levels of height and the lengths of life-expectancy which are selected-for there are not one, but several, available population subsistence equilibria, and the situation is far from being a deterministic one. Factors well beyond the simple availabilty of the food supply have been at work, and many of these factors were 'natural' in origin (climate, disease) while many of the adaptive responses which evolved in conjunction with these natural ones were social in character (delaying childbirth, increasing terms of lactation).

Nevertheless, equilibrium, in some very general sense, was normally attained. To put this in another way, the resource/population process was a homeostatic one in the very long run. Population tended to osscilate around some general equlibrium level (allowing for height and life expectancy differentials) until weather, disease or political disturbance knocked population strongly away from this equilibrium. At this point the combination of positive and preventive checks would serve as some form of pre-modern 'automatic stabiliser', and the population 'carrying load' would eventually once more be brought back towards its long run equilibrium trend (allowing here for some very gradual forms of social learning and technological change). As as result, for the best part of 10,000 years global population size was remarkably stable, and growth in absolute numbers was slow. (Lee, 1987, 1997; Lee and Anderson, 2002),

However it is important to note that while there is plenty of evidence to suggest the existence of such a clear long-term trend, there is also plenty to support the idea that sizeable fluctuations around the trend occured, and that life expectancy in Europe, for example, varied significantly during the centuries preceding the industrial revolution.

Malthus himself, (like Cantillon before him) was an astute observer of the social customs of his times, and he was far from unaware of the wide variety of social institutions and practices - such as age of marriage, the percentage of women marrying, extra-marital fertility, or contraceptive practices - which had evolved and which served to mediate the operation of what some would call our 'naked biological' reproductive potential in determining the number of children per woman actually born.

In fact Malthus himself was well aware that in Western Europe prior to 1800 the key 'preventive check' in operation was what we now call the European marriage pattern. This expression is normally used to describe marriage customs which seem to have been widely practised during a long period of historic time across a substantial part of Europe, and in particular across that part of Europe which lies to the west of an imaginary frontier running from St. Petersburg to Trieste. The pattern has been found to have been in operation to varying degrees from the late middle ages onwards, and it was still to be found operating in some parts of rural Europe as late as the early twentieth century. The high point of its operation, however, is undoubtedly to be found during the seventeenth century.(Clark, 2005)

Malthus himself devoted a large part of Book II of his Essay to describing the marriage system in Western Europe and how it was characterised by late marriage. According to Malthus, the majority of European men and women delayed marriage until they had the economic resources necessary to support their families at their desired standard of living. In this sense many of the modern explanations for the birth postponment process which is thought to characterise the 'second' transition are not necessarily 'un-Malthusian', although it is important to note and understand the importance of the fact that while, during the Malthusian regime, first birth ages fluctuate and adjust to maintain a given standard of living, in the post-Malthusian regime the rise in first birth ages is secular, and associated with a steadily improving standard of living.

Malthus in fact believed that such delayed marriages prevented individuals from experiencing a substantial reduction in their standard of living on marriage and at the same time prevented the population from growing rapidly enough for positive checks and generalised misery to come into play . In particular Malthus noted that delayed marriage was especially widespread in Norway, Switzerland, and England (1986/1803, Vol. 2:238). He also believed that marriage rates in England were so low that a substantial fraction of English biological reproductive capacity was not being used (1986/1803, Vol. 2:239). Malthus in fact says:

“In a review of the checks to population in the different states of modern Europe, it appears that the positive checks to population have prevailed less, and the preventive checks more, than in ancient times, and in the more uncultivated parts of the world. The destruction occasioned by war has unquestionably abated…And although in the earlier periods of the history of modern Europe, plagues, famines, and mortal epidemics were not infrequent, yet, as civilization and improvement have advanced, both their frequency and their mortality have been greatly reduced, and in some countries they are now almost unknown. This diminution of the positive checks to population, as it has been certainly much greater in proportion than the actual increase of food and population, must necessarily have been accompanied by an increasing operation of the preventive checks; and probably it may be said with truth that, in almost all the more improved countries of modern

Europe, the principal check which at present keeps the population down to the level of the actual means of subsistence is the prudential restraint on marriage” (Malthus, 1986/1830:254).

While Malthus did not actually produce a systematic theory to explain delayed marriage, all the elements for such a theory were already present in his writings. As a true child of his times Malthus naturally believed that the aspirations for a respectable standard of living which he felt lead to the delay were based on foresight, and the ability to defer gratification, and these he argued were associated with the higher levels of civilization then to be found in Europe as compared with the majority of the rest of the world.

Thus he attempted to ground the operation of the mechanisms to delay or forego marriage on the psychologically based aspirations of individual women and men. The search for a reasonable (socially determined) standard of living was the central underpinning to the decision to delay marriage, and this constituted the first element in Malthus's system. Postponing marriage, according to Malthus, requires an unwillingness to be patient with pain and misfortune. Whereas expectations and acceptance of future suffering might lead to early marriage, the hope of enjoying life would cause people to postpone marriage (Malthus, 1986/1803, Vol. 2:59). The hope of bettering one’s self and the fear of misery and being without the necessities of life would be motivations to emphasize the preventive check (Malthus, l986/l803, Vol. 3:453-454).

If the first Malthusian element was hope, the second was foresight, the ability to forsee the difficulties that would inevitably attend an early marriage coupled with the rearing of numerous children (Malthus, 1986/1798: 99). Foresight, according to Malthus, requires the ability to look around one and recognize the distress and poverty that normally becomes the lot of those with large families and insufficient means. It requires a certain awareness of the difficulties associated with trying to rear and support children without first being firmly established economically (Malthus, 1986/1803,Vol. 2:14).

And beyond hope and foresight there lies gratification and our ability to defer it. Delayed marriage, according to Malthus, requires an ability to postpone the immediate comforts and satisfactions which might be thought to be offered by marriage with the expectation of receiving even greater benefits at some unspecified point in the future. By delaying gratification, individuals could assure for themselves and their children the resources for respectability and happiness. The comforts and conveniences of life were even possible with delayed marriage (Malthus, 1986/1830: 251-252).

Not everyone, of course, agreed with Malthus. Some took the Bosnerupian - and essentially more optimistic - view that economic resources had a tendency to grow faster than population did. In a Lecture presented at the University of Oxford in 1828, Nassau Senior argued that if what he termed savage nations were in “a state of habitual poverty and occasional

famine” this was due to their inability to develop their productive resources rather than an excess in the growth of their population. If they had but scanty populations, he argued, this was because their means of subsistence were even

scantier. In contrast in every 'civilized' country he found that “there is now less poverty than is universal in a savage state.” and he took the presence of this higher standard of living as testimony to the fact that “the means of subsistence have a greater tendency to increase than the population” (Senior, 1831: 47-48).

Archibald Alison also came to a similar conclusion, arguing that “the rapidity of increase in poulation is in the inverse ratio of the means which are afforded of maintaining a family in comfort and independence: it is greatest when these means are the least, and least when they are the greatest” (Alison, 1840, Vol. 1: 112).

One noteworthy point in both the Malthusian and non-Malthusian accounts is that it was consumption aspirations which played a key role in the explanation. There was however one subtle but important difference between the two views. On the Malthusian account it is the desire to maintain consumption which drives the preventive checks, whereas Senior, Alison, and others believed that consumption aspirations increased rapidly with economic growth, and that it is the desire to keep raising consumption which produces the fertility restraint. Indeed so closely did they believe that delayed marriage was tied to consumption aspirations that they postulated that economic expansion would ultimately lead to the increased postponement of marriage and a reduction in the rate of population increase. In this sense they are undoubtedly 'modern', and in some sense their work foreshadows the recent 'second transition' literature.

In truth the core idea that consumption aspirations increased with economic resources preceded both Malthus and his contemporary critics. Adam Ferguson writing in 1767 had already advanced the modern idea that what is necessary in life is vague and relative. According to Ferguson what is necessary “is one thing in the opinion of the savage; another in that of the polished citizen: it has a reference to the fancy, and to the habits of living” (Ferguson, 1980/1767: 142).

Ferguson went on to argue that there is apparently no limit to the expansion of consumption aspirations. “No ultimate remedy is applied to this evil, by merely accumulating wealth; for rare and costly materials, whatever these are, continue to be sought; and if silks and pearl are made common, men will begin to covet some new decorations, which the wealthy alone

can procure. If they are indulged in their humour, their demands are repeated: For it is the continual increase of riches, not any measure attained, that keeps the craving imagination at ease” (Ferguson, 1980/1767: 143).

Later Archibald Alison was even to offer an intergenerational mechanism for increasing artificial wants. According to Alison “each succeeding generation is bred up in the habits of indulgence to which the preceding one only attained by the result of many years of successful exertion. The parent who has raised himself from the middling to the higher ranks of life, or from the lower to the middling by a laborious industry, communicates to his children the habits and the wants to which he latterly succeeded. The gratifications which were considered as the highest objects of ambition, or the last step of luxury during the best years of his life, are regarded as mere necessaries by his posterity” (Alison, 1840, Vol. 1: 104).

This is, of course, is precisely that ideational mechanism which now plays such a central role in modern models of fertility decline which regularly refer to the way in which aspirations incorporated in such notions as 'ideal family size' tend to evolve with time and across generations (Lutz et al, 2006, Watkins 1990).

Ferguson argued in the eighteenth century that “while arts improve, and riches increase; while the possession of individuals, or their prospects of gain, come up to their opinion of what is required to settle a family, they enter on its cares with alacrity. But when the possession, however redundant, falls short of the standard, and a fortune supposed sufficient for marriage is attained with difficulty, population is checked, or begins to decline.” (Ferguson, 1980/1767: 142-143).

This is, in essence, the cohort theory of fertility change which has sometimes been offered to explain the transition to below replacement fertility. (Easterlin, 1987, Macunovich, 2000). Alison went even further, writing that the increase in artificial wants was the “great and important change” that provided the “principal counterpoise which Nature has provided to the principle of population. The indulgence of artificial wants is incompatible with a rapid increase of the human species. If the labourer finds himself burdened early in life with a wife and children, he must forego many enjoyments which otherwise would be within his reach…Strong as the principle of population is, experience proves that these prudential considerations, when suffered to develop themselves, are still stronger, and are perfectly sufficient to restrain the rate of human increase” (Alison, 1840, Vol. 1: 109-110).

Awareness of the existence and extension of this deferment process was in fact so general that Richard Jones felt the confidence to write that “this self-restraint is so far exercised that there is no record of the customary age of marriage having at any time, in any country, coincided with the age of puberty. Its strength increases, and its sphere of operation enlarges, with the advance of civilization” (Jones, 1859: 245).

The European Marriage Pattern and The Historical Record

Now according to Clark the European marriage pattern exhibited four main features (Clark, 2005):

1. A late average age of first marriage. Typically between 24 and 26 for women.

2. No control of fertility within marriage.

3. Large numbers of women never married. Typically 10-25 percent, but in some populations and periods the percent unmarried was even higher.

4. Low illegitimacy rates. Typically less than 6 percent of all births were illegitimate, even though the majority of women of reproductive age were unmarried. Illegitimacy rates were as low as 1.5 percent in England in some decades of the seventeenth century. French illegitimacy rates were probably even lower.

These four features are important, and their association not merely incidental, since age at first marriage, use of contraception, marriage and illegitimacy rates may be considered as key indicators, one whose movement tends to define the dynamic evolution of any given fertility regime whatsoever.

Clearly embarking on a marriage and establishing a home constitutes a key life course event in any society, and one which is often fraught with difficulty. In this sense early modern Europe is no exception requiring as it does the resources to establish and maintain a separate household (and this would of course be a by-product of the various European family and kinship systems which were in operation, Voland, 2000), and the resulting age at first marriage for women seems to have been typically comparatively late, normally averaging around 25. In fact a substantial proportion of women never actually married (Flinn, 1981, Livi-Bacci, 2000), and, as a consequence, although fertility was high within marriage, the total fertility rate (TFR) was only a relatively modest four to five births per woman (Livi-Bacci, 2000). In England, for example, the mean age at first marriage for women in the mid seventeenth century was 25.9 years and 17.5% of women never married.

Obviously there were considerable differences between social classes here, while rich (and often aristocratic) families reduced their fertility earlier, and often more markedly, than the rest of the population (Livi Bacci, 1986) this was a reversal of an earlier historic trend. During most of the pre-modern period there was a strong correlation between wealth, probability of marriage, younger age at marriage, and completed fertility (Voland, 2000). However, restricted inheritance and the desire to concentrate wealth limited the reproductive value of noninheriting sons and daughters. Thus, as we enter the modern period and as life expectancy improved and economic structures became saturated, resource holding groups began to delay marriage into the late 30s and early 40s for men and mid-20s for women (Szreter and Garrett, 2000; Voland, 2000).Generally, wealth brought a higher probability of marriage at a younger age, to a younger spouse, and more children. However,

as environments became more saturated, and local resource competition among siblings differentially affected resource-holding families, as opposed to day laborers, in a way which increased the likelihood of dispersal of later-born children (Clarke and Low, 1992; Towner, 1999, 2001; Voland and Dunbar, 1997) since the benefits to resource holders of having an above average number of children was increasingly offset by a more and more intense sibling competition for access to inheritance (Voland, 2000). One extreme example of this kind of parental manipulation of offspring marital opportunities was polyandry, in which a male sibship jointly marries a single woman in order to avoid division of property and labor among competing households of wives and children of brothers (Crook and Crook, 1988; Haddix, 2001).

The other interesting detail about the European marriage pattern is the degree of variability which it exhibited. In England, for example, during the seventeenth century limitations on fertility turned out to be so severe that population even began to fall. In the mid-eighteenth century, average age at first marriage fell, and continued to fall, dropping more or less consistently from a seventeenth century high of 25.9 to a low-point of 23.4 by the end of the first half of the 19th century. Over the same time scale the percentage of women never marrying fell to around 7 percent, while the illegitimacy rate (despite the much smaller fraction of the female population at risk of having an illegitimate child) rose from 1.5% to 6%. (Clark, 2005)

A comparable state of affairs to that which existed in England was also to be found in the Verviers region of what is now Belgium, where the average age at first marriage in 1650-59 was 25.3 for women. This rose to 27.5 by 1700-9, before falling again to 25.9 during the years 1730-39. (Alter, 1988, Desama, 1985).

Such changes, while apparently small, actually have quite profound effects on achieved fertility outcomes. At the 1660 low-point, for example, each woman in England had an average of only 1.9 surviving offspring (a figure which seems almost contemporary), by 1815 this figure had risen to 3 children per woman. The consequence was, of course, that during the years of the Industrial Revolution population rose rapidly in England, from 6.7 m. in 1770 to 17.7 m. in 1850, with the increase being partially a product of the fact that the drop in marriage age meant more children being born and being born earlier in the life course. Of course, at the same time morbidity was falling and life expectancy rising, and this was the other component driving the increase in population size. Thus, other things being equal, what can be seen here is that in the area of demography from small changes big things do grow.

Outside of Europe data on mortality or fertility are, unfortunately, only occasionally available for most countries before the World War II era (Preston, 1980), but what little information we do have suggests that the European experience is not a-typical.

Lee and Cambell (1996), for example, show how in Liaoning, China, during the late eighteenth and early nineteenth centuries, despite high marriage rates, within-marriage fertility was only at two thirds of the level found in pre-industrial Western Europe (also see Lee and Feng, 1999 and Cambell, Feng and Lee 2002). They also found that it took longer after marriage for the first child to be born than it did in Europe, and that women terminated their child-bearing earlier. It is not known with any degree of confidence why fertility within marriage in Liaoning was so low, but as in pre-Industrial western Europe there is no clear indication of contraceptive use, and the most likely explanation is the existence of social customs that resulted in and sustained lower fertility levels.

On the other hand recent anthropological research tends to suggest that most pre-agricultural societies limit fertility in a variety of ways. The numbers of births recorded in the few remaining contemporary hunter-gatherer societies, for example, are far below the limits of what is biologically possible, and,indeed, often not dissimilar to those found in pre-industrial Europe. (Ellison, 2001, Kramer and Boon, 2002).

As has been suggested already,prior to the agricultural revolution it is possible to argue that, via the processes which have come to be known as 'natural fertility' (Henry, 1961), human fertility was homeostatically regulated. Such 'natural fertility' was effectively regulated by a combination of fluctuating first-birth-ages and changes in the distribution of births, and these were regulated by a combination of taboos and social practices and by changes in nutrition and other environmentally related factors. That such mechanisms exist in human populations is hardly surprising since virtually all complex organisms exhibit some sort of flexibility in both age-at-first-reproduction and fertility rates. Natural selection it seems has resulted in the appearance of physiological and psychological mechanisms by which both organisms and individuals adjust fertility onset and fertility rates in relation to changing environmental conditions. (Kaplan& Gangestad, 2004 ).

In the case of pre-agricultural hunter-gatherer society this regulation seems to have been achieved by means of a variety of reproductive strategies - such as, for example, extended lactation, or nutritionally and activity driven fluctuating age at menarche - many of which have the characteristic of being biological responses to a constantly changing external environment (Ellison, 2001). Put in other words such mechanisms might well be described as 'natures contraceptives'.

The view that foragers limit fertility so as to maintains their populations in dynamic equilibrium with available resources has become common currency among anthropologists since the 1970s (Dumond 1975; Hayden 1972, 1986).

One source of critique for the standard 'natural fertility view' originates in the work of Hill and Hurtado and their pithy observation that ‘No natural fertility population yet observed is characterized by zero growth, as would be required over much of our species’ history’ (Hill and Hurtado, 1996: 471). Following this work there has been a greater appreciation of the fact that individual energetic efficiency in resource acquisition and production, rather than total productivity rates or the carrying capacity of the environment, may well play the critical part in determining reproduction rates (Belovsky 1988; Hawkes and O’Connell 1992; Winterhalder et al. 1988). Also the idea that human population history has been characterized not by a series of stepped dynamic equilibria but rather a saw-tooth pattern of periods of rapid growth interrupted by infrequent but serious crashes has become increasingly recognized as an alternative explanation for near-zero growth through much of human prehistory.(Blurton-Jones et al. 1999; Boone and Kessler 1999; Hill and Hurtado 1996: 471–2; Keckler 1997).

In any environment in which humans find themselves, there is typically a wide array of animal and plant food items that could be successfully captured, collected, processed and eaten. And yet, rarely is it the case that human populations capture, collect and consume everything that available. In some contexts, human foragers tend to ignore small mammals, reptiles and birds, while, in others, such prey are pursued and consumed. Plants foods that are relatively time-consuming to collect and process, such as acorns or other seeds, are ignored by some foragers, and routinely collected, processed and consumed by others. The question thus arises as to what kinds of factors actually affect how humans choose which food items to pursue, process and consume?

In an important and systematic study of pre-modern fertility patterns, Campbell and Wood elaborate a cross-cultural tabulation of total fertility rates (TFRs) for 70 forager, horticultural, and intensive agricultural societies basing themselves on the contemporary ethnographic record. Their findings show that there is very little significant difference in TFRs across subsistence regimes (Campbell and Wood, 1988). Hewlett carried out a similar analysis of 40 mobile and sedentary foragers and pastoralists. He found the existence of slightly higher fertility rates among pastoralists, although the difference was not significant (Hewlett, 1991).

Bentley et al. subsequently published an extensive critique and re-evaluation of the Campbell and Wood study, presenting their owncross-cultural comparison of 57 forager, horticultural, and intensive agricultural groups. Using a subset of the Campbell and Wood sample, excluding non-independent cases (ethnic groups that were closely related) and populations with high levels of sterility, they found that intensive agriculturalists had significantly higher fertility rates (Bentley et al 1993b).

Although pre-transitional fertility was often higher in the agricultural societies of the third-world in the twentieth century than it was in the earlier European case, its levels were normally far below the hypothetical biological upper limit for a population, which is normally thought to be around 15 to 17 births per woman (Bongaarts, 1978).

The consensus view amongst economists (see eg Kremer 1993) that, on an aggregate level, population growth has been globally slow over the past millennium is almost certainly correct. This slow growth has, however, also been characterised by a puzzling phenomenon of large and significant variance from the mean, with large swings about the growth path being evident - examples of this would be the stagnation in the fourteenth and seventeenth centuries and a more rapid growth rate in the fifteenth and eighteenth centuries. While exchanges of disease (and techniques for treating them) through exploration and trade may have played some role in this, and variability in relations between pathogens and their human hosts may form another part of the picture (Fridlizius 1984; Perrenoud 1984), global climatic change was possibly at the end of the day the principal driving force (Galloway, 1988, 1987, 1986).

What is the Demographic Transition?

The expression 'demographic transition' has been used here extensively, and a number of stylised characteristics have even been offered, but perhaps it is worth looking just a little bit more closely at this concept, its origins, its history and its current useage. The concept is of course a familiar and widely used one. Perhaps it has become just a little too familiar, producing the sort of familarity that breeds if not contempt then at least a 'taking for granted' of the kind which should make us wary, especially when, as will be explained in more detail below, some of its underlying assumptions are being subjected to be continuous questioning and revision. The concept itself may well, in fact, turn out to be something of a "false friend".

The body of theory which undelies our modern concept of the demographic transition was first advanced by Warren S. Thompson’s in a now classic work , "Population" (Thompson, 1929). Thompson in the now time-honoured fashion broke the process of demographic change down into evolutionary stages according to the various levels levels of the birth, death and natural growth rates. Following Thompson's lead the 'theory proper' was subsequently elaborated by a group of Princeton-based researchers - Kinslay Davis, Frank Notestein and Irene Taeuber - in the years immediately after WWII (Davis, 1945, Notestein, 1945, Taeuber, 1945). The theory was really a huge generalisation based on earlier studies they had carried out of mortality and fertility declines, as such it was clearly a product of its times, and of the data which was then available. In particular this meant the Swedish data, which was among the first to be systematically compiled, and which was to mark the schematisation of the transition from the very start.

Taking Sweden as its prototype, the theory attempted to explain the mortality and fertility changes which accompanied the revolution in living standards and social conditions which followed from the agricultural and industrial revolutions of the late eighteenth and early nineteenth century. As has been repeatedly mentioned thought about the transition itself seems from the very begining characterised by an obsession with breaking it down into phases. In what could fairly be called the moden 'authorised version' the phasal structure is essentially presented by Ronald Lee in the following way:

"The classic demographic transition starts with mortality decline, followed after a time by reduced fertility, leading to an interval of first increased and then decreased population growth and, finally, population aging" (Lee, 2003).

This is a pretty normal typology, encapsulating as it does:

i) A pre-transition 'Malthusian' regime

ii) A mortality decline phase

iii) A reduced fertility phase (itself subdivided into (a) an accelerating population growth sub-phase and (b) a decelerating population growth sub-phase

iv) An ageing phase

As we have already noted, population ageing must start from the moment the fertility decline begins. There are however other problems and many of these have long been known. Lee himself draws our attention to the existence of cases in which fertility declined before mortality, most notably the United States and France, while, as mentioned above, in the UK case fertility rose at the same time as mortality declined. As a consequence of the appearance of such anomolies the theory has, over the years, been subjected to considerable criticism. (See Chesnais 1992 for a good summary of the waxings-and-wanings of the theory across time).

Some critics have even gone so far as to suggest that the demographic transition cannot really be characterised as a theory at all (in any meaningful sense of the term) , and would better be seen as a useful rule-of-thumb generalisation. The prestigous Italian demographer Massimo Livi-Bacci once famoulsy proposed that "we should just destroy all this nonsense of transition theory" (cited in Coale 1994). The essential grounds for much of the criticism has been the discovery through subsequent research that the transition itself has, as mentioned above, followed quite different patterns in different places. In fairness to the original Princeton researchers it should be pointed out here that the real fertility-decline part of the transition only began in earnest in the third world with the arrival of the 1960s, while good collection and analysis of much of the European data only took place in the 1970s and 80s. The failure of the transition to materialise in the third world did, of course lead to ridicule being heaped - often most unjustifiably - on the heads of many demographers. Robert Fogel has recently humourously speculated that the hand of some malevelolent deity or other may be at work since there is a clear rule that demographers run out of patience after about 20 years, if what they theorize would happen doesn't happen, and the deity intervenes so that the expected event - in this case the fertility decline - arrives since it was just about the same time as leading demographers began saying the theory of the demographic transition was dead, that the fertility rate in third world countries, including amongst them many Islamic countries, began to decline rapidly (Fogel, 2005).

As suggested above, one problem case for the theory was immediately presented by France, since the French data show that while mortality began to fall in the early nineteenth century just as it did in Sweden, birth rates commenced a long and steady decline at more or less the same time (and here the difference with the Swedish case couldn't be clearer). Consequently what the earlier theorists had called the second and third phases of the transition coincided. Indeed, no substantial population growth corresponding to that which occured in Sweden took place in France. In England, on the other hand, where mortality likewise began to fall early in the nineteenth century, birth rates were actually rising at the same time (Schofield 1984). England therefore experienced a period of extremely high population growth throughout the 19th century.

As has been indicated above, in order to believe in the explanatory value of the original version of the demographic transition theory it is also important to believe in the idea that in the agrarian society preceding the demographic transition, mortality was always at a high level even if varing substantially from year to year. It is, however, precisely this assumption that has provided a second important difficulty for the original version of the theory. The essential idea was that during the so-called 'Malthusian Regime' mortality was high due to a combination of low living-standards (as population tested the limits of agricultural technology) and recurrent epidemics.

However many historical observers soon started to note that death rates in pre-industrial Europe fluctuated widely across decades and across the centuries. Now as long as the theory was based primarily on the Swedish population data (originating in the mid-eighteenth century) the pre-industrial high-mortality data seemed relatively secure. This situation, however was to change as scholars started to realise that before the mid-eighteenth century the European mortality level was far from stable. Patterns of fluctuating mortality had been demonstrated by a number of scholars, but normally only for individual parishes or institutions, or for regions like southern Sweden (Bengtsson and Oeppen 1993) or northern Italy (Galloway 1994). What really put the cat among the pidgeons for the classical version of transition theory was the surfacing the data on English population dynamics (basically these started arriving from the early 1980s onwards) producing a discrepancy which it was impossible to ignore. In particular Wrigley and Schofield - in a study of population in England from the 1540s to the 1870s - found the existence of a markedly different state of affairs to that which would have been anticpated by the standard theory.(Wrigley and Schofield 1981).

Wrigley and Schofield’s classical data provide evidence which is not entirely consistent with a straightforward working of the original Malthusian mechanism. For quite long periods, notably the early 17th century and in the 19th century, there is - in contradiction with what the Malthusian model would anticipate - a simultaneous increase in both population and the real wages. As a consequence there does not appear to be any strong Malthusian type link between mortality and the standard of living in England at this time, and death rates seem to vary in a way which is hard to correlate precisely with the movement of real wages.

The Swedish demographer Bo Malmberg, after an in-depth examination of Wrigley and Schofield’s data, discovered that during the whole period between 1541 and 1871 the English population underwent several cycles of age structure change. Correlating these changes in age structure with the real wage index it became evident to Malmberg that real wages were high when there were large increases in the 30-64 age group. (Malmberg and Sommestad, 2000) He also found a negative correlation between the share of young adults and the real wage. In addition he found these correlations to be valid across the entire 1541 to 1871 period.

Much as Malmberg's work may throw light on what was actually driving the movements in real wages, the mortality problem would appear to be a much more serious one, since if mortality fluctuations cannot be neatly tied down to changes in living standards then this presents real problem for traditional transition theory, since part of the causal mechanism it seems to rely on is called into question.

It is hard here to overstate the importance of the English population studies in initiating the subsequent re-consideration of transition theory, since what these studies did was reinforce the idea that the norms and institutions regulating birth rates, in both the long and the short run, were sensitive to movements in economic indicators, with the important proviso that they did this in a rather surprising way since, it turned out, it was marriage and not mortality which was the principal regulating factor: when times get harder fewer people would get married, producing a simultaneous rise in the marriage age, and a simaltaneous decline in the fertility rate (the 'guilty party' being the now notorious 'tempo effect', which was only really 'discovered and analysed' by Bongaarts and Feeney at the end of the twentieth century, Bongaarts and Feeney 1998).

Thus the work of Wrigley and Scofield was path-breaking in the sense that their results represented a frontal challenge to two of the basic assumptions contained in the original formulation of demographic transition theory. In the first place mortality levels were not high and stable, and in the second it was births, not deaths, which were influenced by the longer-term movements in the economy. Subsequent Swedish studies, which were conducted in the light of the earlier English work, re-examined demographic and economic co-variance in eighteenth century Sweden and came up with results which pointed in a similar direction to the English ones (Fridlizius 1984). Births and marriages were found to be considerably more sensitive to changes in the economy, both long- and short-term, than mortality (Bengtsson 1993, Galloway 1988), and population changes seemed more influenced by economic developments than by social norms.

As I say above, following the initial mortality decline all societies are effectively ageing, the ageing is continuous, and at the present time it is hard to identify a natural barrier to this process. In this sense the transition doesn't really seem to have an 'end state', and thus can hardly be called a transition, since the word transition seems to imply something. If there is in fact a transition it is one from a society homeostatically balanced around high mortality to one which is pivoted around low and steadily declining mortality.

Having said this, and in fairness to Lee, what may be meant by ageing is a society with a comparatively high proportion of dependent elderly. On this view the initial mortality decline creates a dependency ratio which is considerably higher than that in the earlier agricultural society. This 'imbalance' takes many years to correct as fertility rates remain high and societies slowly recover the earlier ratios. But equilibrium is not recovered, and dependency ratios once more start to rise, this time amongst the elderly population. So this is what many may mean by ageing societies: societies where elderly dependency ratios rise (and continue to increase) above a certain notional level.

This way of looking at things has a certain validity, but it does beg one very important - indeed possibly critical from a policy perspective - question: just what do we mean by 'old'. The expression, like the terms modern and post-modern is a deceptive one, since it gives the impression of veing carved eternally in time, when in fact it is, of course, an extraordinarily relative one. To give one illustrative example, one populist Turkish politician got himself elected on a promise to introduce male pensions from the age of 43 and female ones from the age of 39 (something which, of course, resulted in the worst pension's crisis in history). He presumeably thought that 43 was 'old' and those who voted him into power evidently agreed. What we consider to be old is a socially defined (and hence relative) concept. It will hold different values at different times, and as life expectancy reaches ever higher limits we can expect our definition to adjust accordingly. This topic however, will have to await a later stage in the argument to receive the elaboration which it deserves. Simply consider this a foretaste.

Whatever the ultimate verdict on the validity of the phases schema, it should be noted that societies which enter the transition later tend to pass through it at an ever increasing rate. This if we take the mortality decline component we can see that gains in life expectancy have occured in the twentieth century in developing countries at rates which are rapidly by historical standards. In India, life expectancy rose from around 24 years in 1920 to 62 years today (a gain of 0.48 years per calendar year over 80 years), while in China, life expectancy rose from 41 in 1950–1955 to 70 in 1995–1999, (a gain of 0.65 years per year over 45 years.(Lee 2003) Fertility transitions since World War II have typically been more rapid than those for the developed countries, with fertility reaching replacement in 20 to 30 years after onset for those countries that have now completed the transition. Fertility transitions in east Asia have been particularly early and rapid, while those in south Asia and Latin America have been slower in starting but now seem to be accelerating (Casterline, 2001, United Nations Population Division, 2003).

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