The information requested falls within the responsibility of the UK Statistics Authority. I have asked the authority to reply.

The information requested falls within the responsibility of the UK Statistics Authority. I have asked the authority to reply.

Letter from Glen Watson, Director General for ONS, to Lord Laird, dated January 2012.

As Director General for the Office for National Statistics (ONS), I have been asked to respond to your Parliamentary Question To ask Her Majesty's Government why they propose to disaggregate the totals for net migration to indicate the student element when the international standard is to include migrating students; whether they will distinguish between students at universities and those at private colleges: and how they intend to improve the quality of data on students leaving the country [HL4423].

ONS does not intend to remove students from official net migration estimates and will continue to use the UN definition of a long-term international migrant.

ONS uses data from the International Passenger Survey (IPS) to estimate long-term international migration (LTIM) with adjustments made for asylum seekers, people whose intentions change with regards to their length of stay, and migration to and from Northern

Ireland. Net LTIM estimates will continue to adhere to the UN definition of a long-term international migrant, which states that a long-term migrant is a person who changes his or her country of usual residence for a period of at least a year. This definition applies to all migrants, regardless of their reason for migration.

Since 2009, student migration forms the largest single category of long-term migration to the UK. Until January 2012, the IPS only collected information on a person's main reason for migrating. This means that a person may have arrived to study, but left several years later for a different reason, such as work. Therefore it was not possible to identify how many migrants who originally arrived to study have since left the UK.

In January 2012, new questions were added to the IPS to ask those leaving the UK what their main reason for migrating was when they originally arrived in the UK. A further new question asks all emigrants if they have studied while in the UK. These changes will provide better information on emigrants who originally arrived in the UK to study or who arrived for another reason but studied while they were in the UK. These new data, relating to the year ending December 2012, will be available in August 2013.

ONS is unable to distinguish between students at universities and those at private colleges as that information is not collected on the IPS.

The information requested falls within the responsibility of the UK Statistics Authority. I have asked the Authority to reply.

Letter from Stephen Penneck, Director General for ONS, to Lord Laird, dated May 2012

As Director General for the Office for National Statistics, I have been asked to reply to your Parliamentary Question, To ask Her Majesty’s Government, further to the Written Answer by Baroness Verma on 1 May (WA 459-60), what assessment they have made of the Office for National Statistics’ (ONS) conclusion that International Passenger Survey (IPS) figures are the most appropriate source for the calculation of migration figures, given the difference between the ONS Annual Population Survey figure of the increase in the Romanian-born population in the United Kingdom between 2007 and 2010, and the IPS figure used to calculate the Long-Term International Migration assessment of the number of Romanians migrating to the United Kingdom [HL311].

As detailed in PQ response HL1694, we have made an assessment of the different sources of data on international migration and published a report, available at the following link: http://www.ons.gov.uk/ons/rel/migration1/population-by-country-of-birth-and-nationality/sources-of-international-migration-data/differences-between-sources-of-international-migration-data.pdf.

We concluded that the International Passenger Survey (IPS) is currently the most appropriate source for the calculation of long-term international migration based on the UN definition of a long-term migrant, which states that a long-term migrant is a person who changes his or her country of usual residence for a period of at least a year.

We have looked at the Annual Population Survey (APS), but concluded that it is not an appropriate measure of long-term migration flows as it measures “stocks” of migrants and does not differentiate between long and short-term migrants.