Defining Immigrants in the Study
73Appendix 4 Key Datasets Utilised for This Research Report
Table A4.1 Age by Nationality, QNHS Q1, 2011
15-24 (%) 25-44 (%) 45-64 (%) No. of cases Irish 18 45 37 32838 Non-Irish 15 65 20 4103 Of which: UK 12 44 44 755 EU13 16 64 21 348 EU12 13 77 11 1833 Non-EU 14 71 15 1167 All 18 48 35 36941
Source: Own calculations derived from the QNHS microdata Q1 2011.
Notes: Percentages are weighted, no of cases unweighted.
129 CSO Census of Population 2011, Preliminary Results
130 Since Q1, 2009 the QNHS is now undertaken on a calendar quarter basis: Q1; January to March: Q2; April to June: Q3; July to September and Q4; October to December.
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A4.2 The European Survey on Income and Living Conditions (EU-SILC)
The European Survey on Income and Living Conditions (EU-SILC) is an annual household survey carried out in European member states allowing comparable statistics to be compiled across Europe. In Ireland the survey is undertaken by the Central Statistics Office and covers a broad range of issues in relation to income and living conditions of the general population. It is the official source of data on household and individual income and also provides a number of key national poverty and deprivation indicators.
The EU-SILC survey involves both cross-sectional and longitudinal dimensions. The cross-sectional element involves data on households that entered the sample in 2009 (referred to as panel or wave 1); whereas the households in the survey for the second, third or fourth time are considered to be longitudinal households.
The sample design used for SILC is based on the methodology adopted for the Quarterly National Household Survey (QNHS). Both surveys aim to provide a nationally representative sample of private households and use a two stage stratified cluster sample. In 2009, the first stage comprised the selection of 1,690 blocks which are geographically defined continuous groups of households (CSO, 2010). The second stage of sampling involved the random selection of sample and substitute households for each block. The sample was weighted to compensate for both the effects of clustering and to
ensure the sample was representative of the population, though not specifically of non-Irish nationals.
In Q2 2009, households being selected for the EU-SILC survey for the first time or substitute households were drawn from a new sample. Up to this, the 1996 Census was used as a sampling frame, updated using visual enumeration in 2002. From Q2 2009 onwards the 2006 Census of Population was used as a sampling frame (CSO, 2010). This is likely to have had implications for the sample of non-Irish nationals between the two surveys, given the rapid immigration of non-Irish nationals in the period between 2002 and 2006.
Given the sample design the EU-SILC has similar problems representing migrants as the QNHS, concerning asylum seekers, language difficulties and irregular migrants. Given the smaller sample, the issue of representing smaller, hard-to-reach groups is even more challenging. As can be seen from Table A4.3, the proportion of non-Irish nationals is quite a bit lower in the EU-SILC than in the QNHS.131The weighted proportion of non-Irish nationals for all adults aged 15 and over is 9.7 per cent in EU-SILC 2009, compared to 11.5 per cent on the QNHS, Quarter 2 in the same year.
There is a considerably greater proportion of non-Irish nationals in the EU-SILC 2009 sample than in the 2008 sample. In the Annual Integration Monitor 2010, we noted how the weighted proportion of non-Irish nationals for all adults aged 15 and over is 6.9 per cent in EU-SILC 2008, compared to 13.8 per cent on the
Table A4.2 Year of residence by nationality, Q1 2011
Born in 1910-1994 1995-1999 2000-2004 2005-2011 No of cases Ireland (%) (%) (%) (%) (%) Irish 95 2 1 1 1 52,107 Non-Irish 5 7 6 28 54 5,062 Of which UK 9 24 16 23 29 1,031 EU13 3 15 16 21 45 404 EU12 3 0 1 23 73 2,206 Non-EU 4 3 5 44 45 1,421 All 87 3 1 3 5 57,169
Source: Own calculations derived from the QNHS microdata Q1, 2011.
Notes: Percentages are weighted, no of cases unweighted.
131 Some differences in the samples may result from the fact that the EU SILC data draw from a whole calendar year, and the QNHS is one quarter only. That said, the QNHS proportions do not vary so much across the quarters covered by the EU-SILC 2009.
QNHS, Quarter 2 in the same year. This suggests that the 2009 EU-SILC survey is more representative of non- Irish nationals than the 2008 EU-SILC survey.132It is most likely that most of this difference in the EU-SILC samples is attributable to changes in the sampling frame described above.
Once we take into account the under-representation of non-Irish nationals in EU-SILC, i.e. we would expect the weighted QNHS proportions to be about one fifth
higher than the EU-SILC proportions in each case. From Table A4.3 we see that, relative to their proportions in the QNHS sample, in the EU-SILC sample the EU13 group and the non-EU group are over-represented, and the UK group and the EU-10 group are under-
represented, though the differences are not large. The distributions by national group are broadly similar in the two samples (see Table A4.3).
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Table A4.3 Non-Irish Nationals in EU-SILC 2009 and QNHS Q2, 2009
Proportions (Weighted) Proportions (Unweighted) No of cases
(Unweighted)
EU-SILC (%) QNHS (%) EU-SILC (%) QNHS (%) EU-SILC (N) QNHS (N)
Irish 90.4 88.5 92.0 90.9 9,245 64,457 Non-Irish 9.6 11.5 8.0 9.1 809 6,484 Of which: UK 1.9 2.4 1.8 2.0 184 1,423 EU13 1.1 1.1 0.8 0.8 80 606 EU-10 3.5 4.7 2.7 3.7 274 2,605 Non-EU 3.1 3.3 2.7 2.6 271 1,850 Total 100.0 100.0 100.0 100.0 10,054 70,941
Notes: Own calculations using the EU-SILC and the QNHS microfiles. Population aged 15+. EU-SILC data are all those with valid nationality data.