Table 2.

Variables of consolidated data from Erasmus HEIs.

Variable	Description
erasmus_id	The standardized form of the Erasmus HEIs. The first three characters indicate the country. Important: countries denoted by one character contain a double space in this field.
name_local	The local name of the university.
country	The country in which the institution is located.
city	The city in which the institution is located.
lat_city	The latitudinal coordinates of the centre of the city where the headquarters of the institution is located.
lon_city	The longitudinal coordinates of the centre of the city where the headquarters of the institution is located.
lat_POI	The latitudinal coordinates of the headquarters of the institution.
lon_POI	The longitudinal coordinates of the headquarters of the institution.
name_POI	The name of the institution in the POI database.
address_POI	The address of the institution in the POI database.
NUTS3	The NUTS 3 statistical region of the European Union where the headquarters of the HEI is located.
Erasmus_original	The boolean variable that indicates whether the institute is contained in the original database provided by the EU Open Data Portal37. Consolidation of the node set revealed the need to supplement the database of the institution with all HEIs that are contained in the edge set.
ex_stud	The boolean variable that indicates the activity of the institution in terms of student mobility.
ex_teach	The boolean variable that indicates the activity of the institution in terms of teacher mobility.
ex_staff	The boolean variable that indicates the activity of the institution in terms of staff mobility.
ex_any	The boolean variable that indicates the activity of the institution during the 2008–2014 mobility programme between the HEIs. Participation in a trainee programme is not considered in this study.