Opinion
MOSK, J.We granted review in this matter to resolve an issue that has been, and continues to be, much litigated in the lower courts; Is a convicted felon who receives an involuntary civil commitment to the California Rehabilitation Center for narcotic addiction for an offense perpetrated on or after January 1, 1983, entitled to earn credits under Welfare and Institutions Code section 3201, subdivision (c), for good behavior and participation pursuant to Penal Code section 2931—in spite of the fact that subdivision (d) of Penal Code section 2931 states that “[t]his section shall not apply to any person *121whose crime was committed on or after January 1, 1983”? As we shall explain, we conclude that he is not.
I
On his plea of guilty, defendant was convicted in the superior court of the felony of selling cocaine, on or about September 26, 1991, in violation of Health and Safety Code section 11352. Subsequently, he received imposition of a determinate sentence of five years in state prison. Criminal proceedings were adjourned and execution of sentence was suspended pending a determination whether he was subject to involuntary civil commitment to the California Rehabilitation Center on the ground that he was addicted to narcotics, or was in imminent danger of becoming so. After a hearing, he was committed to the center on a finding that he was indeed in such a condition. Criminal proceedings remained adjourned and execution of sentence remained suspended. After he had spent apparently 382 days at the center, he was excluded as unsuitable. Criminal proceedings were reinstated. The original determinate sentence was reimposed. Certain credits were. awarded. But, against his claim for credits that would apparently have amounted to 191 days, none were given under Welfare and Institutions Code section 3201, subdivision (c), for good behavior and participation pursuant to Penal Code section 2931: on the authority of People v. Madison (1993) 17 Cal.App.4th 783, 787, 789-790 [22 Cal.Rptr.2d 157] (hereafter sometimes Madison), such credits were held not to be available, by operation of Subdivision (d) of Penal Code section 2931, because he had perpetrated his offense after January 1, 1983.
After modifying the award of credits in defendant’s favor on grounds not pertinent here, the Court of Appeal affirmed. Adhering to Madison, it upheld the superior court’s denial of good behavior and participation credits on the indicated basis.
On defendant’s petition, we granted review. We now affirm.
II
Section 2931 was added to the Penal Code in 1976 as part of the Determinate Sentencing Act. Since that time, it has authorized the Director of Corrections, in its subdivision (a), to provide credits for good behavior and participation to reduce a convicted felon’s term in state prison under a determinate sentence on a one-for-two basis.
*122Subdivision (c) was added to Welfare and Institutions Code section 3201 in 1980.1 Now, as then, it has stated in pertinent part that the maximum duration of involuntary civil commitment to the California Rehabilitation Center for narcotics addiction for a convicted felon for whom execution of a determinate sentence in state prison has been suspended is the “period of time in confinement or in custody . . . equal to that which he or she would have otherwise spent in state prison had sentence been executed, including application of good behavior and participation credit provisions of’ Penal Code section 2931. It has been construed, as it were, to grant a convicted felon so committed to the center, whether or not he remains for the maximum duration, a “contingent” entitlement to such credits—that is to say, it entitles him to the credits that he would have earned if he had instead served a determinate sentence in state prison. (See, e.g., In re Huffman (1986) 42 Cal.3d 552, 559 [229 Cal.Rptr. 789, 724 P.2d 475].) As its words themselves declare, its purpose is to equalize, at least insofar as these credits are concerned, the maximum duration of an involuntary civil commitment and the maximum term of an executed determinate sentence—in order, apparently, to avoid the deterrence to rehabilitation that would exist if these credits were available in prison but not at the center (e.g., People v. Williams (1991) 232 Cal.App.3d 1643, 1646, 1648 [284 Cal.Rptr. 241]; In re Jiminez (1985) 166 Cal.App.3d 686, 692 -693[212 Cal.Rptr. 550]).
Penal Code section 2931 was amended in 1982 through the addition thereto of subdivision (d), which states that “[t]his section”—with its good behavior and participation credits—“shall not apply to any person whose crime was committed on or after January 1, 1983.”
It is plain to us that the Court of Appeal did not err by upholding the superior court’s denial of credits to defendant under Welfare and Institutions Code section 3201, subdivision (c), for good behavior and participation pursuant to Penal Code section 2931 on the ground that these credits were not available, by operation of subdivision (d) of the latter provision, because he had perpetrated his offense after January 1, 1983. Welfare and Institutions Code section 3201, subdivision (c), entitled him to the good behavior and participation credits that he would have earned pursuant to Penal Code section 2931 if he had served a determinate sentence in state prison instead of receiving an involuntary civil commitment to the California Rehabilitation Center for narcotics addiction. Pursuant to Penal Code section *1232931, however, he could have earned no such credits. That is because, under subdivision (d) thereof, credits of this sort were not available inasmuch as he perpetrated his offense after January 1, 1983.2
In arguing to the contrary, defendant interprets Welfare and Institutions Code section 3201, subdivision (c), to grant a convicted felon who receives an involuntary civil commitment to the California Rehabilitation Center for narcotic addiction an “absolute” entitlement to the good behavior and participation credits of Penal Code section 2931, i.e., it entitles him to earn these credits whether or not he could have done so if he had instead served a determinate sentence in state prison and as a result had been directly subject to the limitation of subdivision (d) of the latter provision to offenses perpetrated before January 1, 1983.
Defendant relies on the canon of statutory construction that “ ‘where a statute adopts by specific reference the provisions of another statute, . . . such provisions are incorporated in the form in which they exist at the time of the reference and not as subsequently modified, and that the repeal of the provisions referred to does not affect the adopting statute, in the absence of a clearly expressed intention to the contrary.’ ” (Palermo v. Stockton Theatres, Inc. (1948) 32 Cal.2d 53, 58-59 [195 P.2d 1].) But the fact is, Welfare and Institutions Code section 3201, subdivision (c), does not adopt Penal Code section 2931 by specific reference. Rather, Welfare and Institutions Code section 3201, subdivision (c), merely states that a convicted felon who receives an involuntary civil commitment to the California Rehabilitation Center for narcotic addiction is entitled to the good behavior and participation credits that he would have earned pursuant to Penal Code section 2931 if he had instead served a determinate sentence in state prison. As explained, a convicted felon, like defendant, who perpetrated his offense on or after January 1, 1983, could have earned no such credits by reason of subdivision (d) of the latter provision. To be sure, Welfare and Institutions Code section 3201, subdivision (c), cites Penal Code section 2931 all but expressly. But that does not effect adoption by specific reference. (See *124generally, In re Jovan B. (1993) 6 Cal.4th 801, 815-820 [25 Cal.Rptr.2d 428, 863 P.2d 673].)3
Defendant next relies on the “equality” and “deterrence-avoidance” purpose of Welfare and Institutions Code section 3201, subdivision (c). That purpose, however, is satisfied most closely by our construction, not his. Our reading ensures that the maximum duration of a convicted felon’s involuntary civil commitment to the California Rehabilitation Center for narcotics addiction and the maximum term in state prison under a determinate sentence had such sentence in fact been executed are equal, and that deterrence to rehabilitation is avoided, at least insofar as the good behavior and participation credits of Penal Code section 2931 are concerned, no matter when he perpetrated his offense. If before January 1, 1983, he would earn at the center the credits he would have earned in prison. If on or after that date, he could not earn at the center the credits he could not have earned in prison. In neither case would he be subject to any deterrence against rehabilitation arising from the availability of the credits in prison but not at the center. Defendant’s interpretation, by contrast, would go beyond ensuring equality and deterrence-avoidance insofar as these credits are concerned: If the convicted felon perpetrated his offense on or after January 1, 1983, he could earn at the center credits he could not have earned in prison, and would receive what defendant deems an “incentive” to rehabilitation. Such additional credits and any resulting incentive may perhaps constitute sound policy. (See In re Jiminez, supra, 166 Cal.App.3d at p. 692.) But it is for the Legislature to give and not this court.
Defendant also relies on Penal Code section 2933. At the time that Penal Code section 2931 was amended into its present form in 1982 with the limitation of subdivision (d) to offenses perpetrated before January 1, 1983, Penal Code section 2933 was added to authorize the Director of Corrections, *125as pertinent here, to provide worktime credits on a one-for-one basis, and worktime-related credits on a one-for-two basis, in the period commencing with that date. Defendant argues that it is “illogical to presume” that the Legislature intended to “dramatically lengthen” involuntary civil commitments to the California Rehabilitation Center for narcotics addiction “while dramatically shortening” determinate sentences in state prison only two years after it added subdivision (c) to Welfare and Institutions Code section 3201 in order to equalize, at least insofar as the good behavior and participation credits of Penal Code section 2931 are concerned, the maximum duration of an involuntary civil commitment and the maximum term of a determinate sentence had such sentence in fact been executed. Contrary to defendant’s implication, any such simultaneous “lengthening” of involuntary civil commitments and “shortening” of determinate sentences would not be attributable to our construction of Welfare and Institutions Code section 3201, subdivision (c). Rather, it would result, in pertinent part, from a restriction of worktime and worktime-related credits to convicted felons serving a determinate sentence (see People v. Eddy, supra, 32 Cal.App.4th at pp. 1106-1110; People v. Madison, supra, 17 Cal.App.4th at pp. 787-789; People v. Abdullah (1992) 6 Cal.App.4th 1728, 1733-1734 [9 Cal.Rptr.2d 131]; People v. Miller, supra, 233 Cal.App.3d at pp. 1553-1556; People v. Williams, supra, 232 Cal.App.3d at pp. 1646-1649; In re Mabie, supra, 159 Cal.App.3d at pp. 305-309; cf. Pen. Code, § 2933, subd. (a) [effectively granting an entitlement to worktime-related credits on a one-for-two basis to convicted felons serving a determinate sentence in state prison who are willing, but not able, to participate in a qualifying worktime assignment]; Cal. Code Regs., tit. 15, § 3044, subd. (b)(2) [similar]; id., tit. 15, § 3044, subd. (b)(5) [similar]; id., tit. 15, § 3044, subd. (b)(7) [similar])—a restriction that he does not dispute.
Finally, we note that, in the course of his argument, defendant asserts that Madison was wrongly decided. We disagree. Its reasoning, which is consistent with our analysis, is sound. Its result, which is identical to our conclusion, is correct.4
Ill
For the reasons stated above, we conclude that the judgment of the Court of Appeal must be affirmed.
It is so ordered.
Lucas, C. J., Arabian, J., Baxter, J., and George, J., concurred.
Defendant requests us to take judicial notice of matter reflected in the Enrolled Bill Report of the California Youth and Adult Correctional Agency of the California Department of Corrections on Senate Bill No. 1878, 1979-1980 Regular Session—the measure that added subdivision (c) to Welfare and Institutions Code section 3201. We hereby do so. (See Evid. Code, §§ 452, subd. (c), 459, subd. (a).)
Not to the contrary are People v. Miller (1991) 233 Cal.App.3d 1551 [285 Cal.Rptr. 410], People v. Williams, supra, 232 Cal.App.3d 1643, In re Jiminez, supra, 166 Cal.App.3d 686, and In re Mabie (1984) 159 Cal.App.3d 301 [205 Cal.Rptr. 528]. None of these cases even considers such propositions as whether Welfare and Institutions Code section 3201, subdivision (c), entitles a convicted felon who receives an involuntary civil commitment to the California Rehabilitation Center for narcotic addiction for an offense perpetrated on or after January 1, 1983, to earn the good behavior and participation credits of Penal Code section 2931. “It is axiomatic,” of course, “that cases are not authority for propositions not considered.” (People v. Gilbert (1969) 1 Cal.3d 475, 482, fn. 7 [82 Cal.Rptr. 724, 462 P.2d 580].)
In re Oluwa (1989) 207 Cal.App.3d 439 [255 Cal.Rptr. 35], on which defendant relies, is distinguishable. It deals with Penal Code section 190, which, although similar in language to Welfare and Institutions Code section 3201, subdivision (c), is nevertheless different from it in substance. (See People v. Eddy (1995) 32 Cal.App.4th 1098, 1106 [38 Cal.Rptr.2d 563].) As explained in the text, Welfare and Institutions Code section 3201, subdivision (c), entitles a convicted felon who receives an involuntary civil commitment to the California Rehabilitation Center for narcotic addiction to the good behavior and participation credits that he would have earned pursuant to Penal Code section 2931 if he had instead served a determinate sentence in state prison and as a result had been directly subject to the limitation of subdivision (d) of the latter provision to offenses perpetrated before January 1, 1983. By contrast, Penal Code section 190 entitles a convicted felon who is serving an indeterminate sentence in state prison of 25 years to life for first degree murder, or 15 or 20 years to life for second degree murder, to earn good behavior and participation credits pursuant to Penal Code section 2931, but without such a condition. (See In re Oluwa, supra, 207 Cal.App.3d at pp. 444-446.)
In his reply brief, defendant asserts that People v. Eddy, supra, 32 Cal.App.4th at pages 1105 to 1106, which generally follows Madison, was itself wrongly decided. Above, we rejected his attack on Madison. Here, we reject his attack on Eddy.