Cal. Gov. Code § 9360.9
Notwithstanding any other provisions of this chapter, the provisions of this section shall be applicable to all allowances granted by this chapter commencing with each installment paid or payable on or after January 1, 1964, with respect to Members of the Senate or the Assembly not having service in such office during or after the term commencing in 1967 and members who are elective officers of the state whose offices are provided by the Constitution and who were first elected to any such office prior to January 1, 1966.
On or before January 1, 1964, the board shall adjust the amount of the allowances payable during the 1964 calendar year to reflect any increase in cost of living occurring between the 1963 calendar year and the 1955 calendar year, inclusive, and any increase resulting from such adjustment shall be payable commencing with each installment of allowances paid or payable on or after January 1, 1964. On or before January 15, 1965, and, on or before January 15 of each year thereafter, the amount of the allowances provided by this chapter shall be adjusted by the board to reflect any increase in cost of living occurring after January 1 of the immediately preceding calendar year. Effective January 1, 1985, the United States city average of the "Consumer Price Index for all Urban Consumers," as published by the United States Bureau of Statistics, shall be used as the basis for determining the changes in the cost of living. For the period from January 1, 1978, through December 31, 1984, the average of the separate indices of the "Consumer Price Index for All Urban Consumers" for the Los Angeles-Long Beach-Anaheim area, and the San Francisco-Oakland area, as published by the United States Bureau of Labor Statistics, shall be used as the basis for determining the changes in the cost of living. For the period prior to January 1, 1978, the average of the separate indices for the Los Angeles-Long Beach area and the San Francisco-Oakland area, as published by the United States Bureau of Labor Statistics, shall be used as the basis for determining the changes in the cost of living. The cost-of-living increase shall equal or exceed 1 percent before any adjustment is made in the allowance. The calendar year 1954 shall be used as the base year in computing any annual adjustment. The annual adjustment made on or before January 15, 1965 and made on or before January 15 of each calendar year thereafter shall correspond to the average annual change in the calendar year immediately preceding the year during which the adjustment shall be effective. The adjustment made on or before January 1, 1964, shall correspond to the total of the average annual changes in each calendar year from the 1955 calendar year to the 1963 calendar year, inclusive.
The adjustment provided by this section shall be made only if it operates to effect an increase over the allowance payable for the calendar year immediately preceding.
Ca. Gov. Code § 9360.9