Sunday, June 2, 2013

Census Comparison

The third release of 2011 census data, allows us to analyse the age profile of  'the big three'. The results are reflected in the graph below:

Using the equivalent data from the 2001 census, we can analyse the age profile of 'the big three' in 2001, The results are reflected in the graph below:

Comparing the data from the two graphs, the most striking question is why has the 'tipping point' (age under which Catholics make up a majority and over which Protestants make up a majority) increased by 12 years instead of 10?  Why has the tipping point which was age 24 in 2001 increased to age 36 in 2011 rather than age 34?

Looking at each of the big three separately might provide some answers. We can do this by bringing the numbers per age as per the 2001 census forward ten years and comparing the changes with the data in the 2011 census. For example, those aged 40 in the 2001 census will be age 50 in the 2011 census.

The 2001 data of course starts at age 10 as those aged 10 and under in 2011 were not born yet in 2001.

The number of 19 to 28 year old Catholics has decreased. The most logical explanation for this is that a significant number of people of this age group are likely to move abroad for education, travel and work.

The number of 32 to 44 year old Catholics has increased. Again this is probably due to people returning from education, travel and work abroad. There may also be an element of immigration from A6 (and predominately Catholic) countries.

From the age of 62 we start to see the number of Catholics decrease and from the age of 69 this trend accelerates. Obviously this can be attributed to increases in the number of deaths as people get older.
The numbers of 18 to 29 year old Protestants has decreased. Again, similar to their Catholic counterparts, many Protestants of this age group are likely to abroad for education, travel and work. However, the Protestant spike at this age group is much higher.

As can be expected, the number of Protestants decreases as more people pass on with old age. This is noticeable from age 56 and accelerates from age 71, similar to Catholics.

However unlike Catholics, the 32 to 44 year old age group has not increased. Possible reasons for this include less Protestants returning after completing their education (we have heard that Protestants are more likely to attend University in Britain and stay on and seek jobs once they have completed their education rather than return to the North) or completing their travels (emigration). There may also be less immigration of Protestants from other countries.

There is not much change among the Others (no religion/none) and this group therefore has no relevance as to why the 'tipping point' has increased by 12 years instead of 10, from age 24 to 36 and not 34. The reason for this appears to lie in the fact that more young Protestants having left and fewer having come/returned have distorted the correlation by 2 years.


  1. Nice work. Graph says it all.

  2. wow thanks for answering my query on your previous post so diligently

  3. The key question is what percentage of other would be people of protestant/catholic backgrounds?

    Of course Northern Ireland would an increasing but still small ethnic population. I'm assumming around 80% of no religion were former protestants and around 20% were catholic. Would that be true? It would appear the PUL community is more secular therefore than the CNR community.

  4. There is a good correlation between age 36 (2001) and age 46 (2011) for both Protestants and Catholics - therefore we would expect the tipping point to be +10 in 2021.

    A interesting question would be when would you expect 'Others' to overtake Protestants at age 0?

  5. 'Im assumming around 80% of no religion were former protestants and around 20% were catholic. Would that be true? It would appear the PUL community is more secular therefore than the CNR community'

    Surely the whole point of the community background question is to mop up all those who are secular, I would have thought a large chunk of the others are a mixture of migrants and children of mixed marriages funnily enough the often laughed at bel tel /lucid poll has SF as the most popular party among that category

  6. NILT survey:

    Irish not British. 24%
    More Irish than British 14%
    Equally Irish and British 17%
    More British than Irish 16%
    British not Irish. 23%
    Other description (please specify) 6%
    Don’t know 1%

    Hat Tip to BangorDub.

  7. The Others at 6.5% are made up of other religions (1%) and no religion (5.5%). The 5.5% has not been allocated to a community background for a reason. I see no reason to allocate any of this percentage to either of the two main blocks.

  8. I see the Belfast Telegraph has issued a correction.

    An online article (‘Protestant-Catholic gap narrows as census results revealed’, posted December 11, 2012) reported on the publication of data from the 2011 Census by the Northern Ireland Statistics Agency and stated that the percentage of Protestants and Catholics in the Northern Ireland population stood at 48% and 45% respectively.
    Protestant-Catholic gap narrows as census results revealed

    We are happy to make clear that this figure in fact referred to the number of respondents raised in the two faith communities, while the figure for practising Protestants and Catholics currently stands at 41% and 40% respectively. Ten per cent of those questioned indicated that they had ‘No religion’. We are happy to clarify the matter.