Academic Legal Writing - Eugene Volokh [96]
So it seems that the focus on the religion of these particular litigants is an arbitrary limitation: If we really want to see whether the Court is biased against non-Christians, we should consider which groups practically benefited from the decisions, and not just who the litigants were. But even if there is some justification for focusing on the particular litigants, this choice should be mentioned and defended (as the cited article, though not the citing book, does), and not just made silently.*
3. More on telling the reader how the result would have come out had the inquiry been worded a bit differently: Finally, the focus on the accommodation cases is itself an unexplained limitation of the sample. As we saw, to be literally accurate, your assertion would need to be not “only Christians ever win free exercise cases [in the Supreme Court]” but “only Christians ever win mandatory accommodation cases [in the Supreme Court]”—but the new assertion, while literally accurate, becomes accurate only by excluding Cruz, Lukumi, and Torcaso.
It's not clear that this exclusion is justified: If the Court were biased against non-Christians, one would expect the bias to show up in the non-accommodation cases as well as in the accommodation ones. But again, even if there's a good reason for treating accommodation cases as unusually probative of the Court's biases, the decision to focus on accommodation cases should be mentioned and defended.
So we can compare the original assertion that you might be tempted to make,
[O]nly Christians ever win free exercise cases [before the Supreme Court]. Members of small Christian sects sometimes win and sometimes lose free exercise claims, but non-Christians never win.
to the more accurate, more informative, and less likely to mislead version:
Only Christian claimants have ever won mandatory accommodation cases before the Supreme Court—five cases total, involving three different religious practices. Some of these cases have also benefited non-Christians who share the same practices (for instance, Jewish Sabbatarians), but the important point is that the particular claimants were Christian, because .... And some non-Christians have won religious freedom cases that didn't involve demands for mandatory accommodation, but the mandatory accommodation cases are the important ones, because ....
The first version is more rhetorically effective, and shorter, than the second. But if you were reading a work to learn about the Court and religious freedom, which of these formulations would you prefer as a reader?
4. Make sure your comparison at least shows correlation, even before you worry about whether it shows causation
Consider this item from a leading online magazine (emphasis added):
The real obstacle to safety reform is that miners no longer have a powerful union sticking up for them. History shows that when miners have: 1) been organized and angry; and 2) had the strong national leadership of the United Mine Workers of America backing them up, they've been able to push for the legislative changes necessary for lasting advances in safety conditions. Sadly, neither of those two factors exist today. In fact, mining in the United States is only safer today than it has ever been because organized mine workers pushed hard for reforms a generation ago—reforms that are still in effect. Whether those reforms are enough is now in question. The majority of mining deaths in the past few years have occurred in nonunion mines.
The implication is pretty clear: