I thought that in this column on September 7th last I had demolished the myth that in a relatively near future Catholics will out-breed Protestants in Northern Ireland.
This is a highly dangerous myth. On the one hand it encourages Catholic triumphalism in the North, which has been disturbingly evident since the recent generous cancellation and re-routing of the Orange marches, and again since the announcement by the IRA of their renewal of the earlier cessation of violence.
At the same time - although on this point a contrary view exists - I believe that this myth reinforces the sense of insecurity and danger that lies behind the hardline attitudes of many unionists.
It is disturbing to see this myth re-emerging last weekend on both sides of the Northern Ireland divide. On this page last Monday Niall O'Dowd referred to the "lurking reality of the demographic tide which could well deliver a nationalist majority in Northern Ireland relatively early in the next century" - citing this as a reason unionists should negotiate now.
And from the other side Barry White, in the Sunday Independent last weekend, echoed this sentiment, referring to the instability that could follow a failure by unionists to negotiate "leading to more radical thinking, and soon the demographic time-bomb, turning the 40 per cent nationalist vote into a majority, could explode."
Now, even if Barry White's more sanguine view as to the impact of this myth on unionists proves better-founded than my more pessimistic opinion on this point, I am convinced that it is profoundly wrong to mislead people on a matter of fact of this kind. And I believe the facts are unequivocal.
Short of a mass exodus of unionists a Catholic majority cannot emerge in Northern Ireland within the first half of the next century, at any rate.
The contrary view is based on developments in the relative birth rates of Protestants and Catholics which began around 1970 but which, far from continuing, were in fact reversed after 1983 - some 14 years ago!
Thereafter, at least until the early 1990s, the proportion of Catholic births declined steadily - as may be seen from the 1991 Northern Ireland Census, which showed that the proportion of Catholic children was lower at each age down from age 9-10 to age 0-1*.
In other words, the Catholic share of the Northern Ireland birth rate was steadily declining from 1983 onwards, dropping during that period from 52.2 per cent to 48.9 per cent. Catholic births in the early 1990s were thus accounting for just under half the total.
Since 1983 Catholic fertility seems to have been adjusting belatedly, but very rapidly indeed, towards the lower Protestant level.
The sharp decline in the Northern Ireland birth rate between 1992 and 1995 suggests that this process has since accelerated further and it seems almost certain that the Catholic fertility rate is now little, if at all, higher than that for Protestants in Northern Ireland.
In this connection it is perhaps worth remarking that in Continental Europe since the mid1980s the traditional differential between low-fertility Protestant and high-fertility Catholic countries has been dramatically reversed.
The lowest birth rates in western Europe are now in Italy, Spain and Portugal whereas in much of northern Europe birth rates have been rising - by as much as one-quarter in Norway and Sweden.
The recent fertility trends in Northern Ireland suggest that this Continental reversal of traditional Protestant/Catholic patterns might yet be replicated in Northern Ireland.
If, as seems likely, the Catholic fertility rate in Northern Ireland now stabilises at, or conceivably even below, the Protestant level, the future population pattern of the North will, subject to possible differential emigration rates, ultimately be determined by the relative proportions of women of child-bearing age from each community.
At present the Catholic proportion of the principal child-bearing age group - 20 to 34 - is just over 45 per cent. But because of the delayed decline in Catholic fertility prior to 1983, this proportion will tend to rise to around, or fractionally over, 50 per cent from about 2010 onwards.
And, if, as seems likely, the fertility rates of the two communities are then similar, there would continue to be a more or less equal number of births to each community - as there has, indeed, been since the late 1970s.
This pattern of equality in births as between the two communities is only now starting to affect the electorate - and some 60 years will have to elapse before this can work its way through the whole voting population.
Naturally, one cannot predict with confidence the trend of future births. But it is difficult to see how any conceivable change in the religious demography of Northern Ireland could produce a Catholic majority much before the year 2050.
So, pace my good friend Barry White, there simply isn't any "demographic time-bomb" likely to explode "soon", nor is Niall O'Dowd right to foresee a "demographic tide" yielding a Catholic majority "in the relatively near future". Unionists need not fear this, nor should nationalists count on it.
In any event, there is no evidence that the emergence of a Catholic majority would yield a majority for Irish unity over the heads of a unionist minority. All available evidence suggests the contrary.
As Mr Jardine pointed out in his paper, (see reference below), in 1967 a Belfast Telegraph poll showed 20 per cent of Catholics preferring the status quo - and only 30 per cent of Catholics then saw an independent united Ireland as their preferred option.
And as the late John Whyte remarked in his book Interpreting Northern Ireland, in only one poll out of 25 conducted between 1973 and 1989 did as many as half of Northern Catholics state a united Ireland as their preferred option. Moreover, in all but one of the annual Northern Ireland Social Attitudes Surveys in this decade, 34 to 36 per cent of Catholics have expressed themselves in favour of remaining in the United Kingdom - as, of course, have 93 to 96 per cent of Protestants.
Of course the remarkable economic growth we have recently achieved might in time reduce the attachment of one-third of Catholics to the United Kingdom. But as long as the weakness of the Northern Ireland economy, and its consequent dependence on huge British subsidies, persists, there will remain a significant proportion of Northern Catholics who will not want to risk the drop in living standard that the loss of the British subsidies would entail - unless, of course, the taxpayers of this State were willing to take on this financial burden - and I would not count on that!
Of course, no one can foresee the pattern of events decades hence.
If the IRA accepted a settlement arising from whatever talks process unionists may agree to engage in, or if, in the absence of such talks, the two governments can devise a settlement acceptable to a majority North and South, the Northern economy might embark upon a delayed growth process similar to that which we are seeing in this State.
And if, as a result of this, Northern Ireland, like this State, eventually caught up with the UK in terms of disposable income per head, and no longer needed British subsidies, much of the reticence about Irish unity amongst Northern Catholics might, however, evaporate.
Finally, if over a similar, or more probably a longer, period a sufficient number of Protestants came to favour switching allegiance to the Irish rather than the British state, some form of political unity of the island might eventually be the outcome.
Such a scenario may seem very improbable but it might not be impossible if, over several generations, the bitterness and hatred generated by the IRA campaign faded in the memories of new generations of people in Northern Ireland.
But what is not going to happen is Northern Ireland falling into a united Ireland as a result of demographic "tides" or "time-bombs". What the gradually-changing demography of the North might, however, produce is a growing acceptance by understanding on the part of many Northern Protestants of the wisdom, in their own self-interest, of taking full account of the rights and aspirations of the Catholic community, whose share of the population will be rising during the next half-century - towards a point of approximate equality with their Protestant neighbours.
* In this article the words "Catholic" and "Protestant" refer to the cultural background of people rather than to their religious affiliation. Those who identified themselves as having no religion or who did not state a religion in the 1991 Census are classified as culturally Catholic or Protestant on the basis suggested by Mr Edgar Jardine of the Northern Ireland Department of Finance and Personnel in his paper on Demographic Structure in Northern Ireland, read to the Statistical and Social Inquiry Society on May 5th, 1994.