Andrew Gelman

Andrew Gelman is a professor of statistics and political science and director of the Applied Statistics Center at Columbia University. He has received the Outstanding Statistical Application award from the American Statistical Association, the award for best article published in the American Political Science Review, and the Council of Presidents of Statistical Societies award for outstanding contributions by a person under the age of 40.

Recent Articles

Chris Schmid on Evidence Based Medicine

Chris Schmid is a statistician at New England Medical Center who is an expert on evidence-based medicine. I invited him to present an introductory overview lecture on the topic at last year’s Joint Statistical Meetings, and here are his slides. All 123 of them. I don’t know how he expected to go though all of these in an hour. You could teach a semester-long course based on this material.

Good stuff, I recommend you all read it.

I’m posting this here because (a) medicine is important in its own right, and (b) the principles of evidence-based medicine also apply to public policy.

Jacobs and Shapiro on how politicians try to mold public opinion

In my NYT column on how to think about conflicting polls, I wrote:

A vast majority of Americans — including half of all self-identified Republicans — think there is “too much power in the hands of a few rich people and large corporations.” And a solid majority believes that “the country’s economic system unfairly favors the wealthy.” On the other hand, close to 60 percent of Americans do not see the country as “divided into haves and have-nots” and over 60 percent see “big government” as the biggest threat to the country in the future. What gives?

I think it’s fair to say that there’s enough here to support different political themes. A supporter of higher taxes for higher incomes can focus on the “too much power in the hands of the rich” angle, whereas a supporter of cuts in low-income and middle-income entitlement programs can focus on the lack of resonance of the haves and have-nots argument.

The ambiguity revealed in these polls actually makes sense: if there were a clear and unambiguous majority in favor of some policy and all its ramifications, we would expect it would have already passed and there would be no remaining political dispute. Democrats and Republicans are no longer arguing about laws against racial discrimination or child labor (with rare exceptions). The very fact that an issue is politically live suggests some flexibility on opinions and helps us understand what otherwise seems contradictory about these poll results. . . .

As the political scientists Lawrence Jacobs and Robert Shapiro have demonstrated, politicians don’t just see public opinion as a constraint; they also use it as a tool to achieve their policy goals. Conflicting majority attitudes — for example, a belief that the economic system unfairly favors the wealthy, juxtaposed with a relative lack of concern for income inequality — represent an opportunity for smart politicians to reshape public opinion their way.

Probability Theory 101

Gregg Easterbrook:

 

Gingrich is a wild card. He probably would end up a flaming wreckage in electoral terms, but there’s a chance he could become seen as the man unafraid to bring sweeping change to an ossified Washington, D.C. There’s perhaps a 90 percent likelihood Obama would wipe the floor with Gingrich, versus a 10 percent likelihood Gingrich would stage an historic upset.

North Korea, East Germany, . . . California

Andrew Sullivan passes on this amusing line from James Pethokoukis:

 

We’ve had some eye-opening natural economic experiments: North and South Korea. East and West Germany. California and Texas. Enough is enough.

The influence of strategic retirement on the incumbency advantage in US House elections

Ben HIghton writes:

Failure to take into account ‘strategic retirement’ leads to inflated estimates of the incumbent electoral advantage. The one attempt to address this issue in the context of US House elections implies that much of the supposed incumbency advantage and most of its presumed increase over time are illusory (Cox and Katz, 2002). This paper identifies possible problems with the Cox and Katz (2002) method and develops a new approach based on simulating the counterfactual condition of incumbents standing for re-election rather than retiring. The results show that when the bias induced by strategic retirement is removed, much of the apparent incumbency advantage and its increase over time remain evident.

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