WALLACE, Circuit Judge,
concurring and dissenting:I agree that when a district court imposes a Youth Corrections Act (YCA) sentence under 18 U.S.C. §§ 5010(b), 5017(c), but suspends execution of the sentence, see 18 U.S.C. § 5010(a), it may not later require the committed youth offender to serve a longer term than permitted by the YCA. The six year statutory limit of subsection 5017(c) begins on the date of conviction, and any modification because of a later probation revocation may not extend the sentence beyond that time. I also agree that if a district court suspends imposition of a YCA sentence and places the youth offender on probation, see 18 U.S.C. § 5010(a), 18 U.S.C. § 3653 does not restrain it in resentencing him, because of a later probation revocation, either under the YCA or as an adult.
The majority, however, also holds that an adult sentence is intrinsically more severe than an equally long YCA sentence, and that when a district court suspends execution of a sentence it lacks the discretion, upon revoking a youth offender’s probation, to find that further YCA treatment will not benefit him. Because I believe this holding unnecessarily straps the district court, is inconsistent with the word and spirit of Supreme Court authority, and ultimately undermines the YCA’s rehabilitative goals, I dissent.
I
In enacting the Youth Corrections Act of 1950, Congress envisioned a rehabilitative program that included “trade training in metal and woodwork ... summer camp with work and recreational programs which keep the boys out of doors ... [and] agriculture and stock raising.” H.R.Rep. No. *12762979, 81st Cong., 2d Sess., reprinted in 1950 U.S.Code Cong.Serv. 3983, 3987. Perhaps the YCA “was the product of a time at which there was much greater optimism than exists today about the possibility of changing behavior patterns of young offenders.” 3 C. Wright, Federal Practice and Procedure § 531, at 159 (2d ed. 1982). Many question the continuing vitality of this rehabilitative ideal. See, e.g., United States v. Amidon, 627 F.2d 1023, 1026 (9th Cir.1980) (the Federal Magistrates Act of 1979 indicates that “the original rehabilitative purposes of the YCA have generally been abandoned”) (dictum); Allen, The Decline of the Rehabilitative Ideal (1981); Martinson, What Works? — Questions and Answers About Prison Reform, 35 Pub.Interest 22 (1974); Van Den Haag, Could Successful Rehabilitation Reduce The Crime Rate?, 73 J.Crim.L. & Criminology 1022 (1982). Nevertheless, absent a clear sign from Congress that it has wholly rejected this rehabilitative ideal, cf. United States v. Donelson, 695 F.2d 583, 588 (D.C. Cir.1982), citing United States v. Hopkins, 531 F.2d 576, 585 n. 51 (D.C.Cir.1976), we may not update the YCA “by judicial legislation under the guise of construction,” Dorszynski v. United States, 418 U.S. 424, 442, 94 S.Ct. 3042, 3052, 41 L.Ed.2d 855 (1974) (Dorszynski), quoting Blockburger v. United States, 284 U.S. 299, 305, 52 S.Ct. 180, 182, 76 L.Ed. 306 (1932). The majority correctly points out that “[w]e possess no power to rewrite legislation.” Majority op. at 1271, quoting United States v. McDonald, 611 F.2d 1291, 1295 (9th Cir.1980). Accordingly, we recently reaffirmed our adherence to thé rehabilitative goals of the YCA. See United States v. Lowery, 726 F.2d 474, 477 (9th Cir.1983); United States v. Bell, 707 F.2d 1080, 1082 (9th Cir.1983).
Implementing the rehabilitative goal requires an allowance of flexibility to the sentencing judge. Thus, “the YCA strongly endorses the discretionary power of a judge to choose among available sentencing options,” Ralston v. Robinson, 454 U.S. 201, 206, 102 S.Ct. 233, 237, 70 L.Ed.2d 345 (1981) (Ralston), so that “the execution of sentence [can] fit the person, not the crime for which he was committed,” Dorszynski, 418 U.S. at 434, 94 S.Ct. at 3048. We have consistently emphasized the broad scope of this discretionary power. See, e.g., United States v. Smith, 683 F.2d 1236, 1240 (9th Cir.1982) (we should resolve any doubt “in favor of maximizing the sentencing options available to district judges”), cert. denied, 459 U.S. 1111, 103 S.Ct. 740, 74 L.Ed.2d 962 (1983); United States v. Weislow, 485 F.2d 560, 562 (9th Cir.1973), cert. denied, 415 U.S. 933, 94 S.Ct. 1447, 39 L.Ed.2d 491 (1974). So has the Supreme Court: the YCA “was meant to enlarge, not restrict, the sentencing options of federal trial courts.” Dorszynski, 418 U.S. at 436, 94 S.Ct. at 3049. The majority, however, seeks to curtail those options. The majority holds, without any statutory or case authority, that equally long adult and YCA sentences differ inherently in their “severity.” Thus, the majority interprets Ralston in an overly narrow, formalistic way.
The majority’s “severity” argument misses the point by stating that the legislative history of the YCA shows a replacement of a retributive with a rehabilitative goal. Majority op. at 1267. This, however, merely illustrates an election among penal policies. Had Congress concerned itself chiefly with ensuring punishments of lesser severity for youth offenders, allowing the sentencing judge vast discretion over whether to apply the YCA at all would appear inconsistent. The YCA, however, clearly allows a sentencing judge to give a youth an adult sentence under section 5010(d), simply by making a “no benefit” finding, without even a statement of justificatory reasons. Dorszynski, 418 U.S. at 425-26, 94 S.Ct. at 3044-45. A defendant has no right to be sentenced under the YCA. United States v. Weislow, 485 F.2d at 562; accord United States v. Mayo, 721 F.2d 1084, 1093 n. 10 (7th Cir.1983). As this indicates, the YCA aims not at sentences of greater or lesser severity, but greater or lesser appropriateness. It provides an alternative sentencing structure *1277for application by the district judge if he believes it appropriate to the individual. See H.R.Rep. No. 2979, supra, reprinted in 1950 U.S.Code Cong.Serv. supra, at 3983 (emphasizing that it is in the opinion of the sentencing judge whether the rehabilitative sentencing of the YCA may fit a particular offender).
The majority next contends that because United States v. Lowery, 726 F.2d at 477, upholds the imposition of a potentially longer YCA sentence than the maximum term available under adult sentencing guidelines, a YCA sentence must be less severe than an equally long adult sentence. The YCA’s rehabilitative aspects do provide “in a sense” a “quid pro quo for a longer confinement but under different conditions and terms____” Carter v. United States, 306 F.2d 283, 285 (D.C.Cir.1962). The exchange involves the receipt of rehabilitative treatment for a possibly longer term, not the receipt of an innately less severe sentence for a possibly longer term, however, and Carter stands for the incommensurability of the two types of sentences. See United States v. Donelson, 695 F.2d at 584 (in Carter “we found no reason to equate the length of a Youth Corrections Act sentence with the length of an ordinary criminal sentence, because of its different purpose ... and effect ... ”).
Despite the temptation to create a slide rule for comparing youth and adult sentences, we gain little by fictional and oversimplified quantifications. In contrast, United States v. McDonald, 611 F.2d 1291 (9th Cir.1980) (McDonald), illustrates that comparison of adult sentencing to adult sentencing, rather than adult sentencing to YCA sentencing, makes sense. In McDonald, the district court found McDonald would benefit from treatment under the YCA and imposed a split sentence. However, it eventually revoked McDonald’s probation, found him unsuitable for YCA treatment, and reimposed the original fine and a seven year sentence. The district court also added a three year special parole term. We found the second sentence impermissibly more severe than the original sentence, thus violating section 3653, because:
Not only was the appellant sentenced as an adult not suitable for handling under the [YCA] but also a special parole term was added which ... probably was not permissible in connection with the original sentence. It is also likely that parole guidelines applicable to the 1976 sentence were more stringent than those which would have been applicable to the 1972 sentence____ These features make it impossible to characterize the 1976 sentence as less severe than that imposed in 1972.
Id. at 1295 (citations omitted). Naturally, because of this comparison of adult parole requirements and guidelines, McDonald does not indicate that an adult sentence, by nature, is more severe than a YCA sentence.
The majority’s other “severity” arguments are similarly weak. The majority emphasizes the opportunities for conditional discharge or expunction provided by the YCA. However, the possibilities for release or expunction all depend on demonstrated progress in treatment under the YCA. They serve as a measure of appropriateness and effectiveness of YCA treatment, and provide no “benefit” for youth offenders who prove devoid of rehabilitative promise.
Lastly, the majority errs in contending that Ralston “appears to acknowledge” that adult sentences are inherently more severe by failing to deny “that by changing a YCA sentence to an adult sentence a court is ‘increasing’ the sentence.” Majority op. at 1269. Because the Court found the common law rule against increasing partially served sentences inapplicable in that case, it did not need to state a view on the issue of severity to reach its result.
II
To arrive at its conclusions, the majority also seeks artificially to limit Ralston. Although it admits that the Court gave its own holding a broad characterization, see majority op. at 1270, the majority argues *1278that Ralston merely dealt with whether a court may modify a YCA term to an adult term after it sentences a youth offender for a federal crime committed during his YCA supervision.1
A person ordinarily has a right not to have a partially served sentence increased in length. This rule, however, “simply does not apply when Congress has provided a court with the power to modify a sentence in light of changed circumstances.” Ralston, 454 U.S. at 218 n. 10, 102 S.Ct. at 244 n. 10. The Court in Ralston focused on judicial discretion in light of the YCA’s rehabilitative goals, and held, in very general terms, that the YCA should not be read as “requiring the judge to make an irrevocable determination of segregation or treatment needs, or as precluding a subsequent judge from redetermining those needs in light of intervening events.” Id. at 211, 102 S.Ct. at 240 (emphasis in original). “Intervening events” must include more than conviction of a federal crime. To read Ralston otherwise would mean that the sentencing judge’s determination of segregation or treatment needs is irrevocable in the absence of such a conviction.
The majority also distorts the spirit of Ralston by fixation on federal convictions. The majority states that an intervening state conviction will not trigger the district court’s power to modify a YCA sentence to an adult sentence, see majority op. at, 1272 n. 15, while a federal conviction will. First, common sense suggests that state convictions may tell just as much as federal convictions about the propriety of continued YCA treatment for a particular youth offender. Keeping hardened criminals, albeit hardened state criminals, in YCA programs may infect others legitimately in these programs and misuse precious rehabilitative resources. Second, the best indicator of a youth offender’s amenability to continued YCA treatment is not the absence of a second conviction, but what he actually did. For example, the act of robbing a bank may indicate he will not benefit from YCA treatment. If the government chooses not to prosecute the robbery, the consequent lack of a conviction does not change the act. Thus, the position of the majority is inconsistent with the pronouncement of the Court. Ralston clearly holds that “a judge may modify the essential terms of treatment of a continuing YCA sentence if he finds that such treatment will not benefit the offender further.” 454 U.S. at 217, 102 S.Ct. at 243.
The policy that best accords with the rehabilitative aims of the YCA lets district judges decide whether any intervening events leading to a probation revocation, not just federal convictions, make further YCA treatment inappropriate. Ralston embodies such a policy, and we are not alone in this interpretation. As the District of Columbia Circuit recently recognized, a rule depriving the district judge of the power to modify a YCA sentence into an adult sentence when the offender will no longer benefit “would result in an inflexible rule requiring the continuation of futile YCA treatment ... and disruption of programs for other offenders who would benefit from YCA treatment.” In re Coates, 711 F.2d 345, 347 (D.C.Cir.1983) (per curiam) (Coates) (citations omitted) (youth offender sentenced to concurrent terms under section 5010(c)). In Coates, the youth offender challenged a “no further benefit” finding made part way through his YCA sentence. No federal conviction intervened. *1279The court concluded that his ease could not “be distinguished from Ralston in any principled way,” id. at 347, and explained that the Supreme Court
recognized that when Congress divested the Bureau of Prisons of discretion to modify the basic terms of confinement for youth offenders, Congress must have intended that the sentencing court may exercise that discretion with respect to those offenders whose conduct during incarceration demonstrates their inability to benefit from further YCA treatment.
Id. The court properly stressed that its decision did not involve resentencing, but merely a modification of “the terms and conditions of ... confinement; the court is thus exercising the same authority with respect to youth offenders that the Bureau [of Prisons] traditionally exercises with respect to adult offenders.” Id. See Ralston, 454 U.S. at 215, 217 n. 10, 102 S.Ct. at 242, 243 n. 10. We, too, should reject the view that the YCA and 18 U.S.C. § 3653 prevent the district court from determining whether the offender would continue to benefit from YCA treatment unless there is a subsequent federal conviction.
Ill
Unfortunately, the majority does not stop with an erroneous interpretation of Ralston, but makes an unnecessary foray into constitutional territory. The rules governing us are clear: “given a valid conviction, the criminal defendant has been constitutionally deprived of his liberty to the extent that the State may confine him and subject him to the rules of its prison system so long as the conditions of confinement do not otherwise violate the Constitution.” Meachum v. Fano, 427 U.S. 215, 224, 96 S.Ct. 2532, 2538, 49 L.Ed.2d 451 (1976) (no liberty interest implicated by the transfer of a prisoner to an institution with different rules). The reduced formality of a probation revocation hearing in part reflects a reduced liberty interest. To the extent the majority argues that this informality points to constitutional infirmities, see majority op. at 1273-1274, it argues counter to established Supreme Court authority. See, e.g., Williams v. New York, 337 U.S. 241, 248-49, 69 S.Ct. 1079, 1083-84, 93 L.Ed. 1337 (1949) (changes in penology from retributive to rehabilitative theories “make it more necessary now than a century ago for observance of the distinctions in the evidential procedure in the trial and sentencing processes.”). Furthermore, a district court may at its discretion impose an adult sentence on a youth offender initially, so the youth offender’s liberty interest seems unlikely to expand simply because of sentencing under the YCA.
The issue of constitutional proportionality is not before us in this case. The majority should, therefore, refrain from reaching out to discuss it. See, e.g., Rescue Army v. Municipal Court of Los Angeles, 331 U.S. 549, 569, 67 S.Ct. 1409, 1420, 91 L.Ed. 1666 (1947). Because the majority’s discussion of that issue is unnecessary to its decision, however, it remains dictum requiring no further comment. See J-R Distributors v. Eikenberry, 725 F.2d 482 at 498 (9th Cir. 1984) (Wallace, J., dissenting).
IV
The overbroad arguments made by the majority will ultimately undermine the YCA’s rehabilitative goals. By holding that an adult sentence is inherently more severe than a YCA sentence, that under Ralston district courts have discretion to find “no further benefit” in a YCA sentence for a youth offender only after an intervening federal conviction, and that the threat of constitutional infirmity lurks in the informal probation revocation process, the majority handcuffs the trial court. For example, the majority argues a probation violation “does not mean that the youths are not suitable for treatment in a YCA facility.” Majority, op. at 1272. That is true — but neither are all youths violating probation still suitable for rehabilitation under the YCA. Cases will arise short of an intervening conviction which involve violations so egregious that a district court could properly find further YCA treatment inappropriate.
*1280The majority assumes that whether a youth will benefit from YCA treatment remains a static proposition. But beneficial treatment now may prove, three years later, a futile effort. In addition, requiring YCA programs to accommodate probation violators who demonstrate their unsuitability for rehabilitation together with those who will still benefit from the YCA wastes what resources the government can apply toward rehabilitation and may defeat the purpose of segregating youth offenders from hardened criminals. Nor can we overlook the possibility that removing the district judge’s flexibility for a “second look” at the time of a probation violation may lead him, despite a wish to impose and suspend a sentence initially, to impose an adult sentence rather than allowing the youth, in a questionable case, to make a final effort at rehabilitation under the YCA.
Thus, although I concur in part of the majority disposition, I dissent from the rest. Until Congress states to the contrary, rehabilitation remains a central goal of the YCA. By insisting that adult sentences are inherently more severe than YCA sentences, giving Ralston an unnecessarily narrow reading, and otherwise removing the flexibility needed for a district court’s continuing determination of the appropriateness of YCA treatment, the majority undermines that central rehabilitative goal.
BROWNING, Chief Judge, and KENNEDY and ALARCON, Circuit Judges, concur in this opinion.
. The majority believes Ralston establishes that it is "pointless to require the government to provide treatment to a youth offender when upon completion of the course the youth will immediately ‘graduate’ to an adult institution." Majority op. at 1272. Inconsistently, the majority does not see that this would be true whether a state or federal conviction prompted the “graduation.” See Majority op. at 1272 n. 15. More fundamentally, however, I do not share the majority's cynicism. If a large amount of time remains under the YCA sentence, and the youth offender will "graduate" to only a short adult sentence, it may not be pointless to have the government provide him continued YCA treatment. The majority's interpretation simply does not adequately distinguish among disparate cases, any more than will the majority’s assertion that a violation of probation not involving a federal conviction never shows the impropriety of continued YCA treatment.