 The necessary  condition holds for the important case of a binary endogenous treatment, leading also to a LATE interpretation with positive weights  .
<meaning-changed>  The necessary  condition holds for the important case of a binary endogenous treatment, leading also to a LATE interpretation with positive weights  .
 The necessary condition holds for the important case of a binary endogenous treatment, leading also to a LATE interpretation with positive weights in a fully heterogeneous model .