wave (1 or 2)
id (in-sample)
MetaID (cross-sample)
Number of employers
1= mail, 2=post, 3=online
Dummy Alina invitation
Dummy Sara invitation
Dummy Jana invitation
Dummy Alina Quality
Dummy Sara Quality
Dummy Jana Quality
0=Private, 1=State
0=small, 1=middle, 2=more than 500
Industries
1, Neu  invited, 0 not invited, . no response
1, Alt+ invited, 0 not invited, . no response
1, Alt- invited, 0 not invited, . no response