California has long adhered to the basic rule that statutes operate prospectively unless the Legislature has clearly indicated it intended retroactive or retrospective application. (Western Security Bank v. Superior Court (1997) 15 Cal. 4th 232, 243, 933 P.2d 507; Evangelatos v. Superior Court, supra, 44 Cal. 3d at p.1207.) The Civil Code itself includes a specific codification of that general principle, declaring, "No part of this Code is retroactive, unless expressly so declared." ( 3.) That statute reflects "the common understanding that legislative provisions are presumed to operate prospectively, and that they should be so interpreted 'unless express language or clear and unavoidable implication negatives the presumption." ( Evangelatos, supra, at p. 1208.) Absent an express retroactivity provision, a statute will not be applied retroactively unless it is clear from extrinsic sources such as legislative history that the Legislature intended that effect. (44 Cal. 3d at pp. 1209-1210.) The presumption against retroactivity applies with particular force to laws creating new obligations, imposing new duties, or exacting new penalties because of past transactions. (In re Marriage of Reuling (1994) 23 Cal. App. 4th 1428, 1439; see Wienholz v. Kaiser Foundation Hospitals (1989) 217 Cal. App. 3d 1501, 1505, 267 Cal. Rptr. 1.) A statutory amendment that imposes a new liability and substantially affects existing rights and obligations will be construed to operate prospectively unless legislative intent to the contrary clearly appears. (Aetna Cas. & Surety Co. v. Ind. Acc. Com., supra, 30 Cal. 2d at pp. 394-395; see City of Los Angeles v. Shpegel-Dimsey, Inc. (1988) 198 Cal. App. 3d 1009, 1019-1020 & fn. 2, 244 Cal. Rptr. 507.) A corollary to these rules is that a statute that simply clarifies rather than changes existing law does not operate retroactively even if applied to acts predating its enactment. A legislative clarification of a statute's true meaning has no retrospective effect because the meaning remains the same. ( Western Security Bank v. Superior Court, supra, 15 Cal. 4th at p. 243; Re-Open Rambla, Inc. v. Board of Supervisors (1995) 39 Cal. App. 4th 1499, 1511.) While we cannot disregard the Legislature's expressed views on the meaning of a statute, a legislative pronouncement that an unmistakable change in the law is only a clarification is neither binding nor conclusive in construing the statute. "Ultimately, the interpretation of a statute is an exercise of the judicial power the Constitution assigns to the courts." (Western Security Bank, supra, at p. 244.)