Political Forecasting: Justin Wolfers vs. Nate Silver

- Andrew Gelman nailed it:

In summary, “-momentum”- can exist, but the places where you’-ll see it is in races where current public opinion is out of step with best predictions. The mere information that a race has a 5-point swing is not enough to predict a future shift in that direction. As Nate emphasizes, such a prediction is only appropriate in the context of real-world information, hypotheses of “-factors above and beyond the direction in which the polls have moved in the past.”-

- As an appendix, and on another topic, compare Justin Wolfers’-s naive view on genders with Steve Blank’-s informed viewpoint.

Pollster John Zogby attacks statistician Nate Silver. – You take other peoples polls, compare records for predictions, add in some purely arbitrary (and not transparent) weights, then make your own projections and rankings.

John Zogby to Nate Silver:

Don’-t Create Standards You Will Find Hard to Maintain Yourself.

Be Honest.

Understand That There’-s Much More to Being a Good Pollster.

Appreciate Innovation.

Do Some Polling.

Nate Silver responds.

UPDATE: Prof Andrew Gelman’-s take.

Nate Silver rates New York Citys neighborhoods… and Jason Ruspini objects.

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Nate Silver rates New York City’-s neighborhoods.

Jason Ruspini:

The piece is problematic insofar as it underweights proximity to areas where people work, which results in high ratings for distant neighborhoods and low ratings for central ones, on top of the effect of higher rents in central neighborhoods. True, if you work from home, it might make more sense to live in the outer boroughs. But if you have a one hour + commute every day, it doesn’-t really help that you happen to live near a subway stop and thus have a relatively high “-transit”- rating.

For the restaurant category, he seems to be considering quantity but not quality. How else does Long Island City have a higher rating than Gramercy/Flatiron, where 9 of the top 50 Zagats restaurants are located? I don’-t even think that Long Island City beats Gramercy/Flatiron in terms of quantity either.

Ultimately, of course, preferences are too subjective to give one ordinal ranking, but the distance-to-average-work-location issue seems glaring, and increases the outer borough bias.

Massachusetts special election: Nate Silver knowns nothing. -REDUX

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Nate Silver:

There are many assumptions in this model which may not be valid []. Although I believe that these are generally a fairly well-balanced set of assumptions relative to the universe of possible assumptions (i.e. alternate sets of assumptions would tend to cluster around the 25 percent number), it is hard to know for sure.