Neil Johnson
tlambert | February 26, 2009This post contains some more notes on a reply to the badly flawed "Main Street Bias" paper.
In my previous post I showed that the MSB papers was wrong to claim that it was plausible that the unsampled regions was 10 times as large as the sampled region. In this post I look at their model. Their model is wrong because it assumes that there is no main street bias in the sampled region and because of this they massively overestimate any bias in the Lancet sampling.
Let's start with a correct model of the situation. I've adopted their terminology where possible.
We have a population of size N…
tlambert | February 19, 2009This post is some more notes on a reply to the badly flawed "Main Street Bias" paper.
The authors claim that it is plausible that the Lancet paper's sampling scheme could have missed 91% of the houses in Iraq. (That is, their parameter n, the number of households in the unsampled area divided by the the number in the sampled area could plausibly be 10 or more.) The only support they offer for this is a reference to this analysis of Iraqi maps.
To the right is a detail from their map. The red lines are main streets and the yellow are secondary streets. They assert that the blue areas are…