Does the estate tax actually work in the US? Our equivalent in Britain appears to be a joke - anyone with a reasonable amount of money can just hire accountants to find some trivial way around it.

I think it's probably the most important tax, in terms of social equity - if you can easily pass down all your wealth from one generation to another, there are no wealth taxes, and capital reliably grows faster than the general economy, that is an obvious formula for the creation of an aristocracy - but I don't know whether it's compatible with the global financial system. Or perhaps it's just British politicians are particularly lackluster on cracking down on obvious avoidance schemes.