dissenting,
with whom RYMER, T.G. NELSON, RAWLINSON, and CLIFTON, Circuit Judges, join.I respectfully dissent from the court’s decision to grant Edmund Chein’s habeas corpus petition based on its conclusion that there was insufficient evidence to convict him of perjury in state court. I do not believe that the State of California deprived Chein of his constitutional rights on these grounds.1
I
Chein was convicted of three separate counts of perjury, the “specialist” count, the “office” count, and the “university” count. I discuss the constitutional sufficiency of the evidence for each conviction in turn.
A
As an expert medical witness at a personal injury trial, Chein was asked the following under oath: “And your specialty, what would be the correct designation?” He answered, “Physical medicine and orthopedic surgery.” While Chein’s residency included some rudimentary training in orthopedic surgery, the actual title of his residency program and consequent speciality designation was “physical medicine and rehabilitation” — not orthopedic surgery. Under California law, a perjurious statement must be both false and material. Cal-Penal Code § 118 (defining perjury as when a person, under oath, “states as true any material matter which he or she knows to be false”). As to the falsity of this statement, the majority ultimately assumes what I believe to be self-evident: that a rational jury could conclude that Chein lied under oath by claiming such a nonexistent credential. See Maj. Op. 985-86.
I disagree with the majority’s conclusion as to the materiality of that lie; specifically, whether a jury in a personal injury case might have been influenced by Chein’s made-up speciality in orthopedic surgery *994when he “testified as an expert witness [to establish] that the plaintiffs would require orthopedic surgery.” Maj. Op. 986. The majority says no. But if two doctors gave me conflicting diagnoses about my need for invasive orthopedic surgery, I know I would be more inclined to trust the opinion of the actual orthopedic surgery specialist over the doctor who practiced physical medicine and rehabilitation. I believe that a rational jury could come to the same conclusion.
Under California law, the materiality of an allegedly perjurious statement is a question for the jury. People v. Kobrin, 11 Cal.4th 416, 425-29, 45 Cal.Rptr.2d 895, 901-02, 903 P.2d 1027, 1033-34 (1995). California’s penal code provides specific detail about this requirement in § 123:
It is no defense to a prosecution for perjury that the accused did not know the materiality of the false statement made by' him; or that it did not, in fact, affect the proceeding in or for which it was made. It is sufficient that it was material, and might have been used to affect such proceeding.2
*995According to California law, a “person is qualified to testify as an expert if he has special knowledge, skill, experience, training, or education sufficient to qualify him as an expert on the subject to which his testimony relates.” Cal. Evid.Code § 720(a). Indeed, when challenged,’’such special knowledge, skill, experience, training, or education must be shown before the witness may testify as an expert.” § 720(a). Thus, Chein’s qualifications, including the correct designation of his specialty, are threshold inquiries that must be established in order for him to testify. In other words, under California law, an expert witness’s credentials are inherently material to his or her testimony.
This is not some “novel per se rule.” Maj. Op. 987 n. 3. Rather, it simply reflects the nature of perjury, under California law, in the context of courtroom testimony. California is generally free to enact rules of evidence establishing when and how witnesses are qualified to testify at trial, and to bar them from testifying otherwise. For example, if a witness is required to have personal knowledge of events in order to testify about them, the fact that he or she did not witness an entire conversation would be grounds for excluding some portion of his or her testimony about it. Likewise, California law required Chein to possess medical credentials in order to offer his expert opinion in the first place — but he lied about the extent of those credentials, and hence about his very ability to testify at all.3 See Cal. Evid.Code § 720.
Indeed, under California law, Chein would have been precluded from offering his opinion if he refused to specify his qualifications, so a rational jury should be able to conclude that lying about those same qualifications was material. See Law Revision Commission Comment to Cal. Evid.Code § 802 (1995)
Under existing law, where a witness testifies in the form of opinion not based upon his personal observation, the assumed facts upon which his opinion is based must be stated in order to show that the witness has some basis for forming an intelligent opinion and to permit the trier of fact to determine the applicability of the opinion in light of the existence or nonexistence of such facts.
(citing Eisenmayer v. Leonardt, 148 Cal. 596, 84 P. 43 (1906) and Lemley v. Doak Gas Engine Co., 40 Cal.App. 146, 180 P. 671 (1919)). The asserted “fact” that Chein was a specialist in “orthopedic surgery” must have been at least one of his “bas[e]s for forming an intelligent opinion,” id., of the orthopedic injuries sustained by the Lopez plaintiffs. Accordingly, the jury was entitled to make its determination “in light of the existence or nonexistence” of that asserted specialty. *996Id. California law also extends the scope of cross-examination in this context to allow an expert to “be fully cross-examined as to ... his or her qualifications.” Cal. Evid.Code § 721(a). Thus, Chein’s lie prevented both the jury and the opposing party from determining a fact that each had the statutory right to consider.
Furthermore, as I understand it, the majority’s interpretation of California perjury law would seem to allow Chein, with impunity, also to have falsely testified that he was a recipient of the Nobel Prize in Medicine for his work in orthopedic surgery.4 For this false, though hugely persuasive credential would only have conferred an enhanced ability to determine “the precise type of surgical procedure” that would be necessary, and would not be squarely relevant to the majority’s critically narrow question of who was better qualified to determine whether the plaintiffs might have “a need for future [orthopedic] surgery.” Maj. Op. 987. This is difficult to accept.
Perhaps, then, this is why the majority is willing to concede that a falsely claimed Nobel Prize in orthopedic surgery “could have been material.” Maj. Op. 987 n. 4 (emphasis in original). But if that is true, it is for a state court jury — not a federal appellate court in a habeas corpus case — to determine whether Chein’s false advanced credential was material. We have no businesses determining, as a matter of state law, that a physician with a Nobel Prize in orthopedic surgery possesses a material expert qualification, while a physician with a recognized specialty in orthopedic surgery plainly does not. In other words, the majority has simply chosen the kind of advanced orthopedic credential it — rather than the jury — finds impressive. I believe such an approach is unwarranted.
This is particularly true given that the expert witnesses at Chein’s perjury trial emphasized the hard work, dedication, and years of advanced training and education it takes to become a “normal, albeit specialist doctor” in orthopedic surgery, as the majority somewhat cavalierly puts it. Id. If nothing else, these witnesses demonstrated that achieving such an advanced credential means a whole lot to them, and that it is certainly an accomplishment worthy of true “recognition ... in a career in medicine.” Id. Nevertheless, the majority says no reasonable person could conclude that such training could potentially have any persuasive value in the Lopez case. With respect, I do not believe California has set so high a bar for perjury convictions.
The majority heavily emphasizes that the defendants in the Lopez case argued that the plaintiffs never suffered any injury at all. See Maj. Op. 988. But that has no bearing in this context. Whatever the defense’s legal theory of the case, the Lopez plaintiffs had to establish the fact of their injuries to recover for them in their tort suit. One of the particular injuries they claimed was orthopedic in nature. Maj. Op. 986 (“Chein testified as an expert witness that the plaintiffs would require orthopedic surgery.”). So if the jury did not believe Chein’s assessment that the plaintiffs had actually suffered those injuries, their recovery would have been reduced accordingly. In other words, regardless of the defense’s position, the plaintiffs had to establish that they actually suffered the orthopedic injuries they claimed in order to receive all of the compensation they sought, and any change in the amount of compensation they may have recovered necessarily affects the outcome of the proceeding.
*997Chein may have lied believing that his testimony would be excluded if he were not an orthopedic surgeon. Or, he may simply have presented a false credential (one that the opposing expert possessed) to bolster his medical opinion testimony. There is also a fair probability that reasonable jurors might specifically consider Chein’s uncorrected lie in making their ultimate determination, at least as to compensation. In any case, a reasonable person could conclude that Chein’s false statement “might have been used to affect[the Lopez ] proceeding.” Cal.Penal Code § 123.
Therefore, I must respectfully dissent from the majority’s conclusion that no rational trier of fact could believe that Chein’s “specialist” testimony was material under California law.
B
The majority also concludes that the jury did not have sufficient evidence upon which to convict Chein of “the office count.” Chein testified that he had only one office, when in fact he had several. Here, the majority clearly concedes that a rational trier of fact could determine that the testimony was false, see Maj. Op. 988-89, but mistakenly holds that no rational jury could have found the essential element of materiality beyond a reasonable doubt.
California courts have interpreted the materiality provision of perjury broadly. For example, “[fjalse testimony even unrelated to an issue but which has the tendency to impeach the credibility of a witness who testified on a material issue may be perjurious” under the materiality requirement. People v. Gamble, 8 Cal.App.3d 142, 87 Cal.Rptr. 333, 335 (1970) (emphasis added). Additionally, false “statements not directly related to an issue may also be material where they have a tendency to influence the trier of fact on an issue.”5 Id.
At least one witness at Chein’s trial, Judge Robert Altman, testified that the maintenance of multiple offices could negatively affect the persuasiveness of Chein’s qualifications because it could lead to the inference that Chein ran “a [personal injury] mill and that the doctor isn’t just in medicine just making money and that the doctor is handling all personal injuries and workmen’s compensation and then churning cases through the courtroom.” This is a simple credibility inference that need not be established by an expert witness, so the fact that Judge Altman was not a medical doctor does not affect the admissibility of his testimony. Judge Altman was a trial judge who presumably adjudicated many personal injury cases involving numerous medical experts and their relative credibility as ultimately evidenced by verdicts. Therefore, his lay opinion testimony was admissible under California law as “[rationally based on the perception of the witness.” Cal. Evid.Code § 800(a).
I sincerely doubt that Judge Altman’s “personal injury mill” inference would “in fact, affect the proceeding in or for which it was made.” Cal.Penal Code § 123. Nevertheless, a rational jury could believe that the false statement “might have been used to affect [the Lopez] proceeding,” *998§ 123, because I believe that a rational juror could conclude that Chein’s false testimony, though perhaps “unrelated to an issue ... ha[d] the tendency to impeach the credibility of a witness who testified on a material issue.”6 Gamble, 87 Cal.Rptr. at 335. Chein’s false testimony also may rationally be understood at least to have had a “tendency to influence the trier of fact on [the] issue” of Chein’s qualification as a credible medical expert. Id. Therefore, I must respectfully dissent from the majority’s conclusion that no reasonable jury could have found Chein’s lie about his offices material beyond a reasonable doubt under California law.
C
Chein’s interrogatory testimony regarding the medical school he attended presents a more difficult question, and one that may hinge on whether or not AEDPA deference applies. Nevertheless, for purposes of this dissent, I need, not address it: Because I believe that there were at least two clearly sustainable perjury convictions, and because there is no suggestion that Chein’s sentence would have been different if he had been convicted only of these two perjury counts, Chein’s incarceration remains constitutionally valid. See United States v. Barron, 172 F.3d 1153, 1160 (9th Cir.1999) (en banc).
II
For the foregoing reasons, I must respectfully dissent.7
. Because I believe the standard of review in this case does not affect the outcome, I, too, express no opinion regarding the interplay between AEDPA and Jackson v. Virginia, 443 U.S. 307, 99 S.Ct. 2781, 61 L.Ed.2d 560 (1979). See Maj. Op. 982.
. The majority asserts that the last part of § 123, "might have been used to affect such proceeding," "seems not to be a definition of materiality but an additional requirement.” Maj. Op. 985 n. 2 (emphasis in original). We have no power to decide how California should best interpret its own law, so such a contention is plainly inappropriate given that the two most recent California cases on the subject specifically define the "materiality” element of perjury as "whether the statement or testimony 'might have been used to affect [the proceeding in or for which it was made].'” Kobrin, 11 Cal.4th at 420, 45 Cal.Rptr.2d at 896, 903 P.2d at 1028 (quoting § 123) (brackets in original); People v. Feinberg, 51 Cal.App.4th 1566, 60 Cal.Rptr.2d 323, 329 (1997). Indeed, in the very case at bar, the California Court of Appeal invoked this standard in rejecting Chein’s sufficiency of the evidence claim.
The majority claims that Kobrin’s formulation is dicta. This is plainly untrue: Kobrin established that the question of materiality must be submitted to the jury, and the specific formulation of that requirement is clearly a valid holding of the court. Indeed, People v. Wade, 39 Cal.App.4th 1487, 46 Cal.Rptr.2d 645 (1995), which the majority relies on to establish the "correct” materiality standard, is not even a perjury case at all, but a second degree murder case that distinguished California perjury jurisprudence. See Maj. Op. 984. Now there’s real dicta.
More importantly, the majority’s analysis suggests that there is some material difference between the "could probably" and the "might” standard, and that only one or the other can apply to this case. See Maj. Op. 984 (arguing that Kobrin did not “overrule earlier formulations of the materiality standard”). I do not believe this to be true, at least under California law. See Feinberg, 60 Cal.Rptr.2d at 329 (stating that "[t]he test for whether a statement is material has been stated as whether the statement or testimony might have been used to affect the proceeding in or for which it was made or whether the statement could probably have influenced the outcome of the proceedings” (internal citations, alterations, and quotation marks omitted)).
Even if they are materially different standards, a “could probably” formulation must be more favorable to Chein than a "might” standard, and the jury's determination under the higher burden necessarily encompassed the lesser finding. In other words, when the jurors specifically found beyond a reasonable doubt that Chein’s false statements could probably have affected the outcome, they perforce found that Chein's lies might have been used to such effect. Longstanding precedent establishes that when criminal "defendants [are] convicted under [a] heavier standard, they have no cause for complaint. The error [can] only work in their favor and [is] therefore, harmless.” United States v. Pheaster, 544 F.2d 353, 362 n. 3 (9th Cir.1976); see also United States v. Rea, 532 F.2d 147, 149 (9th Cir.1976) (refusing to find error in a case where “[a]ny ambiguity in the instructions could only have benefited the defendant, because some jurors might have had an erroneous, but more stringent, view of the government’s burden of proof”).
For these reasons, I must reject the majority’s implication that the "might” standard is not an equally valid formulation of materiality *995under California law. And to the extent it makes any difference at all, I generally employ this baseline materiality standard enunciated in § 123 and reiterated in Kobrin and Feinberg.
. It is undisputed that "Chein testified as an expert witness [to establish] that the plaintiffs would require orthopedic surgery.” Maj. Op. 986. At the very least, then, if Chein admitted that he had not received sufficient training to qualify as an orthopedic surgery specialist, the trial court probably would not have abused its discretion if it determined that he could not testify at least as to that issue. The majority counters that "[t]here is no basis” to conclude that Chein would have been barred from testifying had the trial court known his actual credentials. Maj. Op. 987 n. 3. But this only demonstrates a fundamental misunderstanding of California perjury law, for whether there is any evidence to suggest that a false statement actually may have affected the outcome of a case is irrelevant. Cal.Penal Code § 123 ("It is no defense to a prosecution for perjury that the ... false statement ... did not, in fact, affect the proceeding in or for which it was made.”).
. The simple fact that such a lie would be so easy to detect would have no bearing on a later perjury charge under California law. See Cal.Penal Code § 118.
. Because these statements demonstrate that California law does not confine materiality to any one specific issue in a case, I must reject the majority’s attempt to limit our inquiry to the very narrow question of whether the "number of offices out of which a physician practices [is] material to the question of whether he actually examined the patients about whom he testified." Maj. Op. 991. The jury was free to frame the issues its own way. It could even determine that Chein's lie about his multiple offices was not "directly related to an issue” in the case at all, but merely had "a tendency to influence the trier of fact" in any aspect of its decision. Gamble, 87 Cal.Rptr. at 335.
. While this statement may generally refer to one witness falsely disparaging the credibility of another, I do not believe this is distinguishable from a witness falsely bolstering his or her own credibility. And there is no doubt that Chein testified on a material issue.
. Aside from a sufficiency of the evidence challenge, Chein presented additional arguments to support his petition. Given the court's disposition, however, I do not address them.