Cass Sunstein is a top-rank scholar, and I always learn a lot from his work, even when I think he is ultimately wrong. Unfortunately, however, I fear his recent study (coauthored with Thomas Miles) of judicial "activism" in Supreme Court justices' votes on cases reviewing federal regulatory agency decisions doesn't tell us as much about the subject as one might like. There are three major problems: the way they analyze agency decisions, the failure to consider the possibility that there are centrist ideologies as well as "liberal" and "conservative" ones, and their interpretation of Justice Stephen Breyer's record (the justice they claim is the most "restrained").

Essentially, Miles and Sunstein first code each agency decision as "liberal" or "conservative" (e.g. - a decision to reject an environmental group's claim that a regulation isn't broad enough is "conservative"), and then try to determine how "activist" each justice is by seeing how often they vote to overrule agency decisions. Lastly, they measure how ideologically "partisan" the justices are by determining how often each one voted to overrule "conservative" decisions versus "liberal" ones. Justice Kennedy comes out as the most ideologically "neutral" justice because he voted to overrule conservative agency decisions about as often as liberal ones, while Breyer comes out as the most "restrained" (because he was the least likely to vote to overrule agencies overall).

Here are my three reservations about this framework:

I. What about the Distribution of Agency Errors?

When the Supreme Court reviews agency actions, what they are trying to do is determine whether the agency erred in its interpretation of the federal statute that grants it the regulatory authority in question. Miles and Sunstein implicitly assume that agencies are equally likely to err in a conservative direction or a liberal one. Thus, if Justice Thomas votes to overrule liberal decisions far more often than conservative ones, that shows his ideological "partisanship" in a conservative direction. However, if agencies are more likely to err in a liberal direction than a conservative one - then perhaps his voting pattern simply reflects the distribution of agency errors, not Thomas' ideological biases. Maybe Thomas is the only one fully able to set aside his own biases and focus only on the "true" pattern of agency behavior. Miles and Sunstein's approach can't rule this possibility out. And the same goes for Justice Stevens' apparent tendency to overrule conservative decisions far more often than liberal ones; perhaps that's just a reflection of the agencies' pattern of errors (which may tilt more in a conservative direction), not Stevens' biases. I won't go into detail here, but there are many theories of agency behavior that posit that liberal errors are more common than conservative ones or vice versa.

II. What about Centrist Ideologies?

Miles and Sunstein's framework assumes that there are liberal and conservative ideological biases, but doesn't consider the possibility of centrist biases. Thus, Justice Kennedy is seen as ideologically "neutral" because he votes equally often to strike down liberal and conservative agency decisions. But let's assume for a moment that Kennedy is an ideological centrist, and all he cares about is enforcing that ideology against agency decisions that deviate "too much" from his centrist preferences. He's willing to overrule both deviations in a conservative direction and those that go in a liberal one. Commitment to imposing ideological centrism could explain Kennedy's voting record just as readily as ideological "neutrality." I don't myself know which of these explanations is accurate (perhaps neither is). But the Miles-Sunstein methodology can't distinguish between them.

III. The Special Case of Justice Breyer.

Miles and Sunstein praise Justice Breyer as "the champion of modesty and restraint" because he is the least likely to vote to strike down agency actions overall. Perhaps Breyer deserves this praise. However, it's important to remember that Breyer has a strong ideological commitment to regulatory agency autonomy. In various writings, such as his 1993 book Breaking the Vicious Circle, Breyer has argued that regulatory agencies staffed by expert bureaucrats should be given greater autonomy in order to insulate them from what he regards as harmful pressure from the democratic process. He also believes (for similar reasons) that they should to a large extent be insulated from judicial review. Breyer is a leading defender of the "rule of experts" theory of governance - at least when it comes to regulatory policy. This belief is no less an ideological commitment than is a commitment to conservatism, liberalism, or centrism.

Is Breyer's apparent reluctance to overrule regulatory agency actions driven by "modesty and restraint" or by his ideological commitment to governance by expert regulators relatively insulated from outside control? I honestly don't know the answer; quite possibly both factors are at work. Or maybe neither is. But Miles and Sunstein's methodology can't distinguish between the two.

Thomas Miles and Cass Sunstein have now responded to critics of their study of judicial "activism" and ideological bias in Supreme Court review of administrative agency decisions. To briefly recap the Miles-Sunstein methodology, they code as "activist" justices' votes to overrule agency decisions instead of defer to them, and they characterize the justices as ideologically "partisan" if they are more likely to vote to strike down "conservative" agency decisions than "liberal" ones or vice versa.

In an earlier post, which Miles and Sunstein kindly cite in their reply, I criticized their approach on three grounds: that it fails to control for the underlying distribution of agency decisions (ignoring the possibility that an agency may make more flawed "conservative" decisions than liberal ones, or vice versa); that it ignored the fact that some justices may have centrist ideologies that skew their decisions just as much liberalism or conservative ones; and that their praise of Justice Breyer as the most "restrained" and "humble" justice may be misplaced in so far as he may actually have ideological reasons for maximizing the autonomy of agency bureaucrats.

Miles and Sunstein respond to the first of these points as follows:

If the distribution of agency decisions were skewed in a liberal direction, as some critics allege, we should have observed few or even no challenges from public interest groups. Instead, we observed a fair number of such challenges. Moreover, our study period included many decisions from both the Clinton and the Bush administration, and it would be a big surprise if decisions by the latter were mostly "liberal."

I don't think that if agency decisions were skewed in a liberal direction, it necessarily follows that there would be "few or no challenges from [liberal] public interest groups." The agency could skew in a liberal direction, but the public interest groups might want it to be skewed that way even more. Moreover, an agency skewed in a liberal direction may be more likely to be influenced by challenges from liberal groups to change its policies than one that is conservative. After all, a liberal agency is more likely to sympathize with the agenda of outside liberal critics. Thus, far from preventing challenges to its actions by liberal groups, a liberal-biased agency might actually attract them.

Moreover, the issue in question is not so much whether an agency makes "mostly liberal" decisions as whether it is more likely to err in its interpretation of the law in a liberal direction than a conservative one. If it does, than justices who are more likely to overrule liberal decisions than conservative ones may not be acting in a "partisan" manner, as Miles and Sunstein contend. For example, it's theoretically possible that an agency makes 80% "conservative" decisions, but that half of the 20% that are "liberal" are misinterpretations of the law, while none of the conservative ones are. In such a scenario, the agency makes many more conservative than liberal decisions, but the direction of its errors would still be skewed in a liberal direction. Contrariwise, we might get the opposite result if an agency is more likely to make conservative errors tahn liberal ones.

I am also not convinced that including the Bush administration necessarily protects against the possibility that erroneous agency decisions will skew in a liberal direction. The Bush Administration is a "big government conservative" group that has not paid much attention to regulatory reform, and that has strongly supported massive increases in domestic spending. It would not be surprising if in many agencies, a lot of decisions were left to the permanent bureaucracy (which is often liberal) and if many of those decisions would tend to skew liberal. Such a skew might even be acceptable to those Bush political appointees who approve of the massive growth of government that the Administration has presided over and (for the most part) supported. Probably, any such skew would be smaller than in a Democratic administration, but it may not be nonexistent.

I should emphasize that there are also theories that suggest that agency decisions are systematically skewed in a conservative direction rather than a liberal one. The Miles-Sunstein framework fails to address those theories either.

Lastly, I should note another problem with the Miles-Sunstein categorization scheme. As they note in their response to critics, "[a]gency decisions challenged by industry were deemed liberal, and those challenged by public interest groups were coded conservative." Since Adam Smith, free market advocates have recognized that business interests often favor government regulation when it suits their self-interested purposes. For example, businesses often favor regulations that hobble their competitors. Thus, the fact that an agency decision was challenged by "industry" doesn't necessarily mean that it was "liberal" (at least in the sense of being anti-free market). Similarly, a decision challenged by public interest groups isn't necessarily "conservative." There are now many libertarian and conservative public interest groups such as the Washington Legal Foundation that often challenge agency actions. As Miles and Sunstein correctly note, their coding methodology here is fairly standard in the field. But that doesn't mean that it is unproblematic.

UPDATE: Ed Whelan of the Ethics and Public Policy Center has also written a rejoinder to Miles and Sunstein's reply to his original critique of their study. See here.

In considering Thomas Miles and Cass Sunstein's effort to measure "judicial activism" and the criticism it has generated, I am increasing persuaded that it is impossible to define "judicial activism" in a way that is both 1) useful, and 2) not simply a synonym for incorrect decisions. My tentative sense is that any ideologically or politically neutral definition of "activism" is unlikely to be useful in shedding light on the normative debate over what judicial review should be used for. On the other hand, normatively useful definitions of "activism" will tend to coincide with the analyst's definition of "incorrect decision."

It is certainly possible to define judicial activism in a neutral way. For example, Miles and Sunstein define "activism" in the context of judicial review of regulatory agency decisions as any judicial decision to overrule an agency. Similarly, one can define "activism" in the constitutional law field as any judicial decision to invalidate a statute enacted by a legislature. Such definitions of activism are objective, but not very helpful. Most critics of what they call "judicial activism" don't claim that any judicial decision that invalidates an action by the other branches of government is activist. Instead, they condemn such decisions only if they think they exceed the courts' legitimate authority or misinterpret the relevant law. Thus, knowing that Judge X votes to strike down statutes or overrule agencies more often than Judge Y tells us very little that is useful in determining who is more "activist" in any sense relevant to normative debates about judicial power.

Moreover, both liberal and conservative critics of "activism" often denounce as activist not only decisions that strike down laws, but also those that fail to do so. For a recent liberal example, see here; a recent conservative example is the denunciation of Kelo by some on the right as "judicial activism" (I personally agree that Kelo was wrongly decided, but not because it was "activist").

Of course, we could instead define "judicial activism" not as overruling other branches of government but as doing so without adequate justification. For example, originalists might argue that judges are "activist" when they strike down laws that are not forbidden by the original meaning of the Constitution. In that case, however, the real intellectual work is being done not by the concept of "activism" but by whatever interpretive theory is used to determine whether a given law violates the Constitution or not. For the originalist, the key analytical concept is original meaning or intent; "activism" becomes just another label to attach to decisions that aren't justified on originalist grounds. I don't object if people want to use the word "activist" in this way. But I also don't see how it adds anything to the argument.

There is one group of critics who can use the concept of "judicial activism" in a coherent and analytically useful way. A few scholars - including Robert Dahl and Mark Tushnet on the left, and Lino Graglia on the right - want to abolish judicial review altogether, regardless of the interpretive methodology the judges use. For writers in this camp, it indeed makes sense to define all judicial overruling of the political branches' actions as "activist" and to denounce any such decisions. For the rest of us, however, debates over "activism" are likely to add little of value to the deeper underlying debate over when courts are justified in using their power to strike down the actions of other branches of government.