Ireland, between 1750 and 1840, experienced a tremendously rapid increase in population. The Irish population doubled twice in that period. Whereas in 1750 about 2.5 million people lived in Ireland, in 1791 this number had already increased to 4.4 million and reached 8.2 million in 1841. According to Kennedy and Clarkson estimates show that population growth in Ireland during that period was 'higher than anywhere else in western Europe'. What were the reasons for this startling growth in population?
There are several possible reasons for population increase that have to be taken into consideration: first, a declining death rate; second, an increasing birth rate; and third, an immigration rate that would exceed emigration. The latter is definitely not true for Ireland. As Connell points out:
"Since the seventeenth century immigration into Ireland, though of some importance culturally and economically, has been numerically insignificant. Emigration, far from helping us to solve our problem, increases its magnitude: the last twenty-five years of rapid population-increase were also years of heavy emigration."
Population increase in Ireland between 1750 and 1840, therefore, has to be either the result of an increasing birth rate or a decreasing death rate; or, which seems much more likely, the result of both. This paper, however, is going to argue that the rising birth rate was of much greater importance, especially if you compare the actual degree of population growth in Ireland with that in other western European countries.
If one argues that both the falling death rate and the rising birth rate account for the massive growth in population in mid eighteenth till mid nineteenth century Ireland, one has to ask for the socio-economic changes that caused both these developments. This essay is going to point out that both the falling death rate as well as the rising birth rate were caused by the almost complete reliance on the potato as the single source of food in Ireland's rural areas. As Connell states, the almost exclusive reliance on the potato by the end of the eighteenth century was a 'recent development'. Until the mid eighteenth century the potato was of much less importance for the Irish people's food supply. Most people, at that time, only supplemented potatoes to a diet that mostly consisted of oatmeal and dairy products.
"[…] the potato, three-quarters of a century after its introduction to the country, was, for the greater part of the year, a supplement to the traditional foodstuffs […] If there is no conclusive evidence of the primacy of the potato in the Irishmen in the early seventeenth century there is authority, fully as convincing, supporting the position that a century later the potato was sill far from occupying the place in the Irishman's life which it had achieved by the nineteenth century."
One major change in Irish society, then, was the growing importance of the potato from the mid eighteenth century up to the Famine years. As population explosion is always caused by major social and economic changes the growing reliance on the potato as the Irish people's source of food could explain the rapid population increase after 1750.
There are two major arguments in favour of this assumption. First, the good nutrition of the new kind of potatoes that were sowed in Ireland at this time caused a falling death rate, especially among children. At the same time, good nutrition resulted in encouraging earlier marriages and therefore a rising birth rate. Secondly, the potatoes are fast growing crops and high yields can be achieved on small patches of land, which, moreover, do not even have to be very fertile. This led to division and subdivision of land in Ireland, enabled more people to marry earlier and therefore to get more children.
As Connell points out, good nutrition led to a lower incidence of disease, on the one hand, and, at the same time, encouraged people to marry earlier and get more children. Although it is certainly true that good nutrition lowers the risk of dying from diseases the incidence of small pox and fever, for instance, remained very high in Ireland up to the Famine years. Mortality rates, if at all, only fell slightly and, above all, not more than in England, where, on the other hand, population grew much less rapidly.
"Taking the long view, mortality was generally low between the mid eighteenth and mid nineteenth centuries. It possibly drifted slowly upward so that on the eve of the Famine the death rate in Ireland was similar to that found in its more heavily industrialized and urbanized neighbour."
Therefore, one has to assume that the population explosion in Ireland after 1750 was rather due to a rising birth rate than to a falling death rate. One reason for this, however, certainly was that the nutritious potato encouraged people to earlier and more fruitful marriage. People had enough and healthy food to raise a number of children. And, as children were needed on a farm to give a helping hand when they were older and to grant security of the living standard of their parents later on, peasants always tended to have a lot of children, as long as they could afford it.
Peasants could afford to have more children, however, because of several advantages of the potato crop. First of all, the potato was easier to grow than any other crop, above all than wheat, which had been the Irish people's main source of food up to the mid eighteenth century. Potatoes grow on nearly every sort of soil. Therefore, new patches of land were available for peasants in Ireland's bog and mountain land. Whenever there was a patch of land available for a single man to build a farm on it and thus being able to afford the upholding of a family, he could marry and get children. This utilization of new land, therefore, contributed to the rising of the birth rate in Ireland.
A second advantage of the potato is that, compared to wheat for instance, one needs a much smaller patch of land to supply the same number of people with food.
"On the assumption that a man would eat 9 pounds of potatoes a day, or 4 pound of wheaten bread, an acre would support six potato-eaters for a year, substantially more than three times the number of bread-eaters.
The cultivation of the potato, therefore, enabled farmers to divide their holdings among their children. This again encouraged farmers to get more children since they were able to grant a certain grade of security for them. Until the eighteenth century it was only the eldest son who would be certain to get the farm and therefore to lead a secure family life. Division of land, in those times, was not possible because both tillage and stock farming demanded large holdings. Thus, the other children, at least the other sons, had to find another basis of their existence: most of them either became labourers or emigrated to America or Great Britain. Through division and subdivision of farmland it was possible that each of the sons of a farmer could get his own patch of land - their future security was granted.
Furthermore, those sons were able to marry much earlier than they would have been if they had had to find another opportunity to afford their own existence, not to mention that of a wife and children. Each of the sons of a farmer, therefore, would have more children than if he had married at an older age. Moreover, each of those sons, again, would be able to divide his farm among his own sons - so for him the same reasons as for his father occur to get lots of children.
Division and subdivision of land, then, was only possible because of the cultivation of the potato. It led to more and earlier marriages and, thus, to a rising birth rate.
Connell, however, points out that this is just one side of the medal - subdivision at the same time, was an effect of the rapid population increase.
"In the last quarter of the [18th] century potato culture and subdivision, each both cause and effect of the other, became jointly cause and effect of the increase in population: the wilder the pace of population-growth, the more insistent was the trend towards a diet almost exclusively of potatoes."
This indicates another issue concerning population increase in general and population increase in Ireland in particular. In fact, the growing population itself causes an even higher increase in population. If more children are born, more people grow up to get even more children who grow up to get even more children, and so on. Clearly, this is what happened in Ireland in 1750-1840. At least three generations of Irish people grew up in that period. If one assumes that already in 1750 more children were born than in the generation before - which seems likely for the above mentioned reasons - population would already have been multiplied in 1775, again in 1790, 1815 and so on. This is, of course, a rather theoretical approach to explain population increase, but in fact this is what happened in Ireland. In 1754 there were 2.4 million people living in Ireland, in 1777 the number had increased to 2.5 million, in 1790 there were already 3.8 million people living in Ireland, in 1813 5.9 million and in 1831 7.8 million. Of course, the assumption that an increasing population forces itself to increase even more, does not take into consideration the various famines that took place in Ireland over that period and caused many deaths. The same is true for the large number of people who emigrated from Ireland. However, it illustrates roughly the development of population in general. This process, of course, has to stop somewhere; and population growth actually slowed down in the last decades before the Famine. People realized that this development became more and more dangerous since there would come a time when subdivision of land was not possible anymore, when the patches became too small, even for the potato.
Nevertheless, the further growing of population would not have been possible if the circumstances mentioned above had been different. The excessive cultivation of the potato and the resulting subdivision of land caused Irish people to marry earlier and get more children; and it were the same things that caused those children, once they had grown up, to get married early and get a lot of children as well. Population increase in Ireland from 1750-1840, then, is linked with earlier and therefore more fruitful marriages, which, on the other hand, were caused by the almost exclusive cultivation of potatoes. The rising birth rate, therefore, was of much higher importance for Ireland's population increase than the falling death rate. The extraordinary increase in population in Ireland compared to other western European countries is obviously due to the Irish people's exclusive reliance on the potato as their source of food, a development that, to that extend, occurred in none of the other countries.