Cal. Const. art. IV, § 4

(a) To eliminate any appearance of a conflict with the proper discharge of his or her duties and responsibilities, no Member of the Legislature may knowingly receive any salary, wages, commissions, or other similar earned income from a lobbyist or lobbying firm, as defined by the Political Reform Act of 1974, or from a person who, during the previous 12 months, has been under a contract with the Legislature. The Legislature shall enact laws that define earned income. However, earned income does not include any community property interest in the income of a spouse. Any Member who knowingly receives any salary, wages, commissions, or other similar earned income from a lobbyist employer, as defined by the Political Reform Act of 1974, may not, for a period of one year following its receipt, vote upon or make, participate in making, or in any way attempt to use his or her official position to influence an action or decision before the Legislature, other than an action or decision involving a bill described in subdivision (c) of Section 12 of this article, which he or she knows, or has reason to know, would have a direct and significant financial impact on the lobbyist employer and would not impact the public generally or a significant segment of the public in a similar manner. As used in this subdivision, “public generally” includes an industry, trade, or profession.
(b) Travel and living expenses for Members of the Legislature in connection with their official duties shall be prescribed by statute passed by rollcall vote entered in the journal, two-thirds of the membership of each house concurring. A Member may not receive travel and living expenses during the times that the Legislature is in recess for more than three calendar days, unless the Member is traveling to or from, or is in attendance at, any meeting of a committee of which he or she is a member, or a meeting, conference, or other legislative function or responsibility as authorized by the rules of the house of which he or she is a member, which is held at a location at least 20 miles from his or her place of residence.
(c) The Legislature may not provide retirement benefits based on any portion of a monthly salary in excess of five hundred dollars ($500) paid to any Member of the Legislature unless the Member receives the greater amount while serving as a Member in the Legislature. The Legislature may, prior to their retirement, limit the retirement benefits payable to Members of the Legislature who serve during or after the term commencing in 1967.
When computing the retirement allowance of a Member who serves in the Legislature during the term commencing in 1967 or later, allowance may be made for increases in cost of living if so provided by statute, but only with respect to increases in the cost of living occurring after retirement of the Member. However, the Legislature may provide that no Member shall be deprived of a cost of living adjustment based on a monthly salary of five hundred dollars ($500) which has accrued prior to the commencement of the 1967 Regular Session of the Legislature.