Adrian wrote:

For taxi users to be less likely to be affected, less than 50% of them
would be affected. I'm suggesting that is not the case, and you're
interpreting that suggestion to mean that taxi users are 50% of the
populace.

This is nonsense.

Let's take it step by step.

The original point is that taxi passengers can well afford higher fares to
cut the particulate output that disproportionately affects more deprived
groups, as per the stroke paper, resulting in health costs that are almost
certainly higher than fitting emission controls.

In other words, I'm saying that taxi passengers in London are not the same
group as the group affected most by pollution. You are saying they either
are or could be.

Perhaps it will help you to visualise a black cab belching its way down the
Mile End Road. Is the passenger most likely to be:

A City stockbroker
A Bangladeshi woman with diabetes
Adrian
Lord Lucan.

E.