Cal. Const. art. XIII § 16
The county board of supervisors, or one or more assessment appeals boards created by the county board of supervisors, shall constitute the county board of equalization for a county. Two or more county boards of supervisors may jointly create one or more assessment appeals boards which shall constitute the county board of equalization for each of the participating counties.
Except as provided in subdivision (g) of Section 11, the county board of equalization, under such rules of notice as the county board may prescribe, shall equalize the values of all property on the local assessment roll by adjusting individual assessments.
County boards of supervisors shall fix the compensation for members of assessment appeals boards, furnish clerical and other assistance for those boards, adopt rules of notice and procedures for those boards as may be required to facilitate their work and to insure uniformity in the processing and decision of equalization petitions, and may provide for their discontinuance.
The Legislature shall provide for: (a) the number and qualifications of members of assessment appeals boards, the manner of selecting, appointing, and removing them, and the terms for which they serve, and (b) the procedure by which two or more county boards of supervisors may jointly create one or more assessment appeals boards.
Cal. Const. art. XIII § 16