Before revision:  I characterize an informativeness condition under which this retention rule is endogenous, provided that the principal uses an opaque information policy -- she observes the delegate's policy choice and outcomes, but not the effort.
After revision:  I characterize an "informativeness condition" under which this retention rule is endogenous, provided that the principal uses an opaque information policy -- she observes the delegate's policy choice and outcomes, but not the effort.