Census 2011 has led to substantial revisions to the inter-censal population estimates published by the Central Statistics Office (CSO). These revisions are attributed mainly to the underestimation of migration flows for the years 2007-2011; data from the previous Census from 2006 were not revised. Adjusted natural increases for the period (based on vital statistics) accounted for the remaining differences between revisions to annual population and cumulative migration. Figure 1 shows the annual population underestimations for 2007-2011, mainly comprising cumulative net migration. In total, the April 2011 population was revised upwards in Census 2011 by 90,600.
Source: Research notes – Quarterly Economic Commentary – Winter 2012