the local average treatment effect (late), also known as the complier average causal effect (cace), refers to the treatment effect among compliers. the late may not be of the same value as the average treatment effect (ate), so extrapolating the late directly should be done cautiously. in addition, the late retrieved from an experiment may not immediately be externally valid, especially when there is a case for treatment effect heterogeneity (i.e. the treatment effect varies across individuals).  however, generalizing the late through reweighting can be attempted, given certain key assumptions.