A Baumslag-Solitar group is a group with group presentation 
for nonzero integers 
(Baumslag and Solitar 1962).
Gaboriau et al. (2026) classified these groups into three measure equivalence classes. The first consists of the amenable cases 
or 
. The second consists of 
, and the third consists of 
with 
. In particular, all groups in the third class are measure equivalent.
