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6 October 2006

Causation and Manipulation, V

Jim Greiner

Fair warning: This entry includes a plug for one of my papers

Anti-discrimination laws require lawyers to figure out the causal effect of race (gender, ethnicity) on certain decision making. Previous posts have been exploring the often-tossed-around idea of considering the treatment to be perceived race, as opposed to "actual" (whatever that means) or self-identified race, to answer the no-causation-without-manipulation objection. This feels like a good idea, but it really only works in some cases and not others. It works when we can identify a specific actor (or an institution) whose behavior we want to study. Capital sentencing juries and a defendant firm in an employment discrimination lawsuit are two that work. We can think about changing these specific actors' perceptions of particular units (capital defendants, potential employees), and we can think about WHEN it makes sense to think of treatment (the perception) as being applied: at the moment the actor first perceives the unit's race (or gender or whatever). In contrast, "the public" or "the set of all employers in the United States" are two examples of actors that don't work. The timing of treatment assignment no longer makes sense, the counterfactuals are too hard to imagine, and the usual non-interference-among-units assumption becomes hard to think about.

What does all this buy us? A fair amount. First, this line of thinking identifies cases in which rigorous causal inference based on the potential outcomes framework remains beyond our reach. Figuring out the causal effect of gender or salaries nationwide is one example; another is the causal effect of candidate race on election outcomes. Second, in those cases in which we can identify a specific actor, we get a coherent conceptualization of the timing of treatment assignment, which allows us to distinguish pre- from post-treatment variables. This is a big deal. Entire lawsuits sometimes turn on it.

All this has important implications for civil rights litigation, as I discuss in my paper, "Causal Inference in Civil Rights Litigation." You can get a draft (pdf) of this paper from my website, which you can access by clicking on my name to the left. I'd appreciate any reader reactions/suggestions.

Posted by James Greiner at 10:19 PM

Andrew Gelman

Boston Chapter of the American Statistical Association Evening Lecture Series

"Rich state, poor state, red state, blue state: What's the matter with
Connecticut? A demonstration of multilevel modeling"

Andrew Gelman, Columbia University*

IQSS, 1737 Cambridge Street, Room N354

Monday, October 9, 7:30pm

* Andrew will also be on hand at IQSS on the morning of Tuesday, October 10, to answer any stats questions you might have.�

Posted by Gary King at 12:31 PM