(a) Each determination to pay a supervisory differential shall be made in writing under procedures established by each agency.

(b) The procedures established by each agency under paragraph (a) of this section shall provide that—

(1) Each determination to pay a supervisory differential, including the amount of such differential, shall be reviewed and approved by an official of the agency who is at higher level than the official who made the initial decision, unless there is no official at a higher level in the agency; and

(2) In determining whether to use the authority under 5 U.S.C. 5755 and this subpart and in determining the amount of such differential, the relationship in pay among supervisors under the General Schedule in the same organizational component of the agency shall be considered, as well as the relationship in pay between the supervisor and his or her subordinate(s).

(3) Each determination to pay a supervisory differential shall be documented.