An Op-Ed that was published in The Hill is calling on Rachel Maddow and Jon Stewart to issue corrections over their inaccurate coverage of the first GOP debate on Fox News. According to political scientist Scott Liebertz, the political pundits have not been doing “the right math” and as a result, both Maddow and Stewart’s segments this week regarding the margin of error in the polls used to decide the debate lineups were wrong.
Liebertz breaks down both where Maddow and Stewart went wrong:
Both Jon Stewart and Rachel Maddow, for example, mocked Fox’s criteria last week as being what the latter called “totally arbitrary,” based on what is ironically their “totally” mistaken understanding of margin of error. Or more precisely “margins” of error, because that is essentially what exists – many different calculations of sampling error when there are several different options for respondents to choose from. So when George Pataki sits at less than 1 percent in the polls it makes no sense to say that with an overall survey margin of error of 3 percent, he may actually be as high as 4 percent. Trust me, he isn’t that high. Yet this is precisely the case made by Rachel Maddow on a recent segment of her show, saying of Pataki’s .4 percent: “If you factor in the best case scenario with the margin of error, maybe he’s at something more like 3.4 percent…That would put him above John Kasich and it would put him on the stage.” Sorry George but no stage for you. Maddow went on to proclaim “I can do the math!” Unfortunately she didn’t do the right math.
On “The Daily Show” Jon Stewart made a similar error to Maddow when he chastised Fox News by mockingly musing “what do you do when…I don’t know…the last four qualifying spots for your debate are locked in a statistical tie with the margin of error?” It wasn’t clear which polls Stewart was using, but for the sake of demonstration, let’s look at the current Real Clear Politics average (as of 7/31). Though Stewart’s statement was a bit confusing, I assume he meant that those candidates currently in positions 7-10 could just as easily be somewhere in between positions 11-16 and vice versa. This would mean, for example, that Rand Paul in 7th place with 5.5 percent is actually trailing Rick Perry in 11th place at 2.2 percent. But if we ditch the overall margin of error for the correct margin of error of the difference of proportions, we get a more accurate picture. Treating the RCP average as one poll with a sample size of 450 (the average of the 6 polls), Paul’s lead of 3.3 percent is as high as 5.8 percent or as low as .8 percent, but in either extreme he still leads Perry and we can logically assume he leads the remaining field as well.
On why corrections should be issued:
But when prominent political pundits misinterpret sampling margin of error to misinform the public (and in mocking tones to boot) it is worth making a correction.
So, will Jon Stewart issue a correction during one of his two remaining shows? Let us know what you think in the comments section below.