This document presents research on using Facebook advertising data to investigate migration trends of Europeans to the UK. The researchers aim to create a weekly time series of European migrant populations in the UK since December 2017 to analyze if Brexit has impacted migration. They compare Facebook estimates to official data and find similarities. Preliminary results show Facebook data estimates 7.8 million migrants in the UK out of 39 million Facebook users, with breakdowns by country of origin, age, education level over time. The researchers plan to develop a Bayesian model to project future migration trends.

1. “Brexodus?”:
A Longitudinal Approach to Investigate European
Migration to the UK Using the Facebook
Advertising Platform
Francesco Rampazzo, Jakub Bijak, Agnese Vitali, Ingmar
Weber, and Emilio Zagheni
European Population Conference 2018
Rampazzo, Bijak, Vitali, Weber, and Zagheni “Brexodus?”: European Migrants in the UK with FB Advs Data

2. New Strand of Research
Migration data is poor in quality. Definitions vary by country.
Use of Big Data for complementing traditional data sources
through the re-purposing of datasets.
Literature: Mobile Phone Record, VOIP (Skype, Whatsapp),
Social Media (Facebook, Twitter, LinkedIn), Search Engine
(Google, Baidu).
Advantage:
Geo-located
Global data availability
Homogeneous dataset
Data for under-studied
dimensions
Disadvantage:
No metadata
No control over the variables
Bias and non-representative
data
Rampazzo, Bijak, Vitali, Weber, and Zagheni “Brexodus?”: European Migrants in the UK with FB Advs Data

3. The Praxis: Calibration
Use of calibration techniques for modeling the systematic bias of
the on-line data with ground truth data.
Example:
“Leveraging Facebook’s Advertising Platform to Monitor Stocks of
Migrants” by Zagheni, Weber and Gummadi (2017).
Facebook’s Advertising Platform data with the American
Community Survey.
Rampazzo, Bijak, Vitali, Weber, and Zagheni “Brexodus?”: European Migrants in the UK with FB Advs Data

4. Objective
We are creating a weekly time series of stocks of European
migrants in the UK, with data coming from Facebook’s
Advertising Platform.
Our aim is to fill the gap of the traditional data sources and
project future trends of European migrants.
COUNTRYOFORIGIN
AGE
Rampazzo, Bijak, Vitali, Weber, and Zagheni “Brexodus?”: European Migrants in the UK with FB Advs Data

5. Objective
We are creating a weekly time series of stocks of European
migrants in the UK, with data coming from Facebook’s
Advertising Platform.
Our aim is to fill the gap in the traditional data sources and to
help project future trends of European migrants.
COUNTRYOFORIGIN
AGE
Rampazzo, Bijak, Vitali, Weber, and Zagheni “Brexodus?”: European Migrants in the UK with FB Advs Data

6. Contribution
We want to contribute to this field of research by looking at the
European Migration to the United Kingdom.
Three Reasons:
1 Immigration to the UK
2 Brexit
3 Migration Data
Rampazzo, Bijak, Vitali, Weber, and Zagheni “Brexodus?”: European Migrants in the UK with FB Advs Data

7. 1. Immigration to the UK
It was in 1979 that the UK first recorded a positive net migration.
The Office of National Statistics (ONS) reports for 2017 9.4
million non-UK born population.
40% of the non-UK born population are European citizens.
The top 5 nationalities are Polish (1 million), Romanian (411,000),
Irish (350,000), Indian (346,000), and Italian (297,000).
Rampazzo, Bijak, Vitali, Weber, and Zagheni “Brexodus?”: European Migrants in the UK with FB Advs Data

8. 2. Brexit
Since the Brexit Referendum, European migration has started to
decrease.
Rampazzo, Bijak, Vitali, Weber, and Zagheni “Brexodus?”: European Migrants in the UK with FB Advs Data

9. 3. Migration Data
The UK (im)migration data sources are fragmented and measure
different populations.
There is no ground truth in the UK.
Sources:
Numerosity Measures
International Passenger Survey (IPS) 800,000 interviews Flow
of which 4,000 migrants
Labour Force Survey (LFS) Sample of 40,000 Stock
Annual Population Survey (APS) Sample of 300,000 Stock
National Insurance Number (NINO) Register data Flow
Home Office Visa Application In-Flow
Census Census Stock
Hesa Census Students Stock
Rampazzo, Bijak, Vitali, Weber, and Zagheni “Brexodus?”: European Migrants in the UK with FB Advs Data

10. Research Questions
1 How does European migration to the UK change by week
since December 2017?
Do we observe a decline in migrant stocks during the Brexit
period?
2 Can Facebook Advertising data complement traditional data
sources in the UK?
Rampazzo, Bijak, Vitali, Weber, and Zagheni “Brexodus?”: European Migrants in the UK with FB Advs Data

11. Facebook Data
We download the data from
https://www.facebook.com/ads/
manager
Use of the variable Expat(...).
In the Adverts Manager’s
documentation, Expats are defined
as “people whose original country
of residence is different from the
current country”.
We disaggregated the data by age,
sex, and educational level, but also
for England, Wales, Scotland, and
Northern Ireland.
Rampazzo, Bijak, Vitali, Weber, and Zagheni “Brexodus?”: European Migrants in the UK with FB Advs Data

12. Preliminary Results
The dataset is made up by 39,000,000 Facebook users which are
anonymized, aggregated groups within the UK, of whom
31,000,000 are British, and 7,800,000 are migrants (at December
18 2017).
These figures include Facebook users older than 15 years old.
Rampazzo, Bijak, Vitali, Weber, and Zagheni “Brexodus?”: European Migrants in the UK with FB Advs Data

13. European migrants: ONS and Facebook Estimates
ONS: Annual Population Survey data for 2017;
Facebook: European Migrants estimates for October 2017 age 15+.
Rampazzo, Bijak, Vitali, Weber, and Zagheni “Brexodus?”: European Migrants in the UK with FB Advs Data

14. Eurostat and Facebook European Migrants Population
Pyramid in the UK
Rampazzo, Bijak, Vitali, Weber, and Zagheni “Brexodus?”: European Migrants in the UK with FB Advs Data

15. Education Distribution of the European Migrants in the UK
Rampazzo, Bijak, Vitali, Weber, and Zagheni “Brexodus?”: European Migrants in the UK with FB Advs Data

16. Time Series: Polish, Romanians, and Italians in the UK
Rampazzo, Bijak, Vitali, Weber, and Zagheni “Brexodus?”: European Migrants in the UK with FB Advs Data

17. To be continued ...
Downloading the weekly stocks of European migrants, and
constructing a Bayesian Model on the style of the IMEM model.
Adapted by Disney (2015).
Rampazzo, Bijak, Vitali, Weber, and Zagheni “Brexodus?”: European Migrants in the UK with FB Advs Data

18. Thanks!
Francesco Rampazzo
@chiccorampazzo
F.Rampazzo@soton.ac.uk
Acknowledgements: This work is supported by the Economic and Social
Research Council through the South Coast Doctoral Training Partnership
[Project: ES/P000673/1].
Rampazzo, Bijak, Vitali, Weber, and Zagheni “Brexodus?”: European Migrants in the UK with FB Advs Data