This post is about the abortion debate, an atypical subject for me but I'll be writing about it in relation to my customary concerns about quantitative thinking. All I want to say about it is that whenever I try to follow the debate, I become frustrated by the vague propositions people use to frame the question. Here's an example, a graph from Pew:
The poll asks, "Do you think abortion should be legal or illegal in all or most cases?" The trouble with this is that there's no time axis in the question. I think for a large fraction of people---not everyone, certainly, but for a significant number of people---their actual views about this question depend strongly on how far along the pregnancy in question happens to be.
For a significant number of people the answer is, "Legal up to a point"---which makes it important to ask, "Up to what point?" But none of the polls seem to ask this question.
For each n = 1, 2, 3, ..., what percentage of Americans would outlaw abortion-on-demand in week n if they could do so? Is there any research on this?