Ms Helen Lowry:

It is possible to calculate the number of people on deportation orders since the enactment of the Immigration Act 1999. There have been 22,459 deportation orders signed, of which 4,564 were enforced. Therefore, we can estimate that there were 17,895 non-enforced deportation orders in Ireland. We can also estimate that the rate of voluntary return of migrants is 13.8%. That is sourced from ongoing meetings with the Department of Justice and Equality and data we have been able to glean from the Department. This means 2,470 people of the estimated 17,895 non-enforced deportation orders would have left Ireland voluntarily. Therefore, an estimated 15,425 people have non-enforced deportation orders in Ireland. That is an informed estimate.

With regard to people who overstay a visa, that is a more difficult figure to calculate, as I mentioned earlier. As the committee can see from our research, over 90% of people we surveyed were not in a formal process with the State. They are just getting on with their lives, like the Irish in the United States. They are not in a process of legally doing something about their position. I do not want to bore people to tears but this is important. Those who overstay their visas are undetected migrants in the State, which include tourists, people from non-visa requirement countries, student visa holders and others. We can make the data available to the committee afterwards. If we use coefficients from research conducted by Gordon et alin 2009, entitled "Economic Impact on London and UK Economy of an Earned Regularisation of Irregular Migrants to the UK", we can make a very informed estimate of the number of undetected migrants in Ireland. We do not really use such language, although it is in the report. The research identifies a coefficient to calculate the number of undetected migrants based on the numbers of undocumented migrants known to the authorities. It is a residual method. The study was pioneered in the UK but it offers the most appropriate measurement tool as the UK has the most similar immigration system, geographic boundaries and immigration flows to Ireland.

From this we were able to examine the 15,000 cases I mentioned with respect to deportation orders, as well as other data from the Department of Justice and Equality, to do a coefficient sample. Based on the residual methodology, the following calculations can be made. A low-estimate coefficient, at 9.58%, would have 1,796 cases and a medium coefficient, at 22%, would have 4,279 migrants. This may be corresponded with numbers of undocumented people coming through the drop-in centre. A high-estimate coefficient, at 36%, has been chosen, resulting in an estimate of 6,761 undetected migrants in Ireland. We selected the coefficient and used it to calculate the numbers. If we add the undetected numbers to the cases we know, we can extrapolate the number of between 20,000 and 26,000, depending on whether we use the low, medium or high coefficient.

The element of children is important. Coefficients were obtained from the study to calculate the number of UK-born children as a percentage of the overall undocumented population. These coefficients, when applied to various estimates of undocumented migrants in Ireland, generated the following figures. There is a figure of 2,400 for the low coefficient, 3,672 for the medium coefficient and 5,100 for the high coefficient. That is why we have indicated consistently that we estimate there is between 2,000 and 5,000 undocumented children in Ireland. That is very difficult to estimate as children would not be registered anywhere and would not be until they are older. That is some of the rigour behind the figures.