"Figure 10: Preliminary Home Office administrative data results compared with IPS data – long-term migration, UK, 2016 to 2017","" "","" "","" "Notes","1. ONS analysis using methodology detailed within the [Report on international migration data sources: July 2018](https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/internationalmigration/articles/reportonthecomplexityandqualityofinternationalmigrationstatistics/july2018) (first arrival and last departure date where available, otherwise visa length for work, study, family and other types of visa or permission to stay in the UK). 2. Comparisons of the Home Office administrative data and IPS estimates illustrate that there are differences between the measures of migration available from the two sources; for example, in the: data being collected (intentions vs operational travel details); way it is collected (face-to-face survey vs operational systems); quality (both sources will include unit and item non-response or recording errors, IPS estimates will include sampling error whilst administrative data is affected by the processes from which the data is obtained); and assumptions made to process the data. Neither source directly measures whether an individual is usually resident whilst in the UK or elsewhere. 3. All numbers are rounded to the nearest thousand. Totals may not sum due to rounding." "Unit","Persons" "","" "","Other","Study","Family (accompany or join)","Work" "HO data - Immigration","6000","106000","77000","42000" "IPS - Immigration","8000","94000","49000","71000" "HO data - Emigration","2000","91000","29000","30000" "IPS - Emigration","8000","37000","11000","24000"