On the subject in the title: Personal import allowances, compared Working notes rather than a conclusion.
I have spent a fortnight trying to pin personal import allowances down and I want to set out where I have got to, because I suspect the honest answer is duller than the thread this will produce.
What I have: a consistent observation across a small number of cases, collected the same way each time. What I do not have: any controlled comparison, or any reason to think my cases are representative.
The specific question is whether the pattern survives once the obvious confounder is removed. I cannot remove it with what I have.