Polling averages

Very inside baseball, but for the political junkie poll-watching types (hmmm, maybe sound familiar to anybody who reads or writes this blog?) I thought this was a very interesting post by TNR’s Nate Cohn about how the changing composition of the Real Clear Politics polling average is likely driving apparent changes in relative poll standing more than actual changes in voter opinion:

Take the RCP average, which only considers the last two or three weeks of polling. As a result, only a handful of polls are usually represented. The decision to privilege timeliness over comprehensiveness is entirely justifiable, since a shorter window will pick up shifts in the race more quickly than a less sensitive long-term average. But so far in 2012, there haven’t been genuine shifts in the race—so poll-watchers haven’t yet reaped the benefits of responsive, narrow time-frame polling averages (although they will after the conventions). Instead, the polling averages are shifting with the changing composition of the pollsters included in the average—and their house effects.

If all polls were released at similar intervals, this wouldn’t create systemic bias. But Gallup and Rasmussen release polls every day, so they’re always in the RCP average. So, even though Gallup and Rasmussen are just two of 20 or so national pollsters, they usually represent anywhere from one-third to one-sixth of the RCP average. In contrast, Pew Research, which consistently shows Obama leading by 4-to-7 points, generally releases polls once a month. And for good measure, they produce huge sample sizes, accrued over long periods, so they’re kicked out of the polling average sooner than they would if they surveyed fewer individuals over one weekend…

This is a relatively minor issue, but a 1-to-1.5 point difference in the RCP average affects perceptions of the election. Analysts often give the impression of a deadlocked race, but while the race is close, Obama actually has a clear and narrow lead.

On a quasi-related note, Nate Cohn has bee producing lots of top-notch analysis of the election yet I never see any of the usual suspects  link to him.  They should.  (Also just discovered his latest post is noticing this exact problem in the latest pollster.com averages).


Photo of the day

Went to the Carolina Hemlocks State Recreation Area yesterday for an extended family picnic.  Good time were had by all (except by my eldest David who just thought the whole thing was stupid).  Took lots of great photos with my new 50mm F/2.0 lens (notice the amazing bokeh).  This isn’t the best from a photographic perspective, but it is my favorite for obvious reasons:

Get over it

I don’t spend a lot of time on twitter (as this Post story focuses on), but I’ve seen enough on Facebook, that I just need a mini-rant against all the NBC haters.   The Olympics are always on tape delay and the internet is not going to change that.  You spend a billion dollars on the Olympics of course you need to recoup that money during the dramatically more popular (lots of people actually have to work during the day) and more lucrative evening hours for television.  Should the just run the gymnastics live during the day when way fewer people can see them?  (They already stream it on-line free for the die-hards).  Should they run their evening coverage on the assumption you already know?  “You probably saw on-line that Gabby Douglas won the gold, forget any drama, here’s how it happened.”  Ummm, of course not.  It is a little frustrating to actually avoid my favorite new sources every day to avoid Olympic spoilers?  Sure.  But I’m so tired of people blaming NBC for simply practicing capitalism (and giving me exciting sports drama every evening).

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