Many companies, including a fair few of Germany's biggest, pay no trade tax at all.
In 2000, a bumper year, the trade tax yielded DM1 billion ($470m) more than expected.
Cameron wants the event to be about the three Ts – trade, tax and transparency.
The UK will regain legal control of things like trade, tax, economic regulation and energy.
But on top of it is added a German speciality called Gewerbesteuer, or trade tax (which is 14% on average).
Trade tax, a corporate tax that is the biggest source of local revenue, is rebounding with the economy.
That is why the G8's trade, tax and transparency agenda is so important.
Britain's prime minister, David Cameron, wanted the summit to focus on the three Ts – trade, tax and transparency.
In return, Mr Schäuble wanted to scrap the trade tax and replace it in part with a municipal right to vary income tax.
And municipalities still resist the idea of abolishing the trade tax.To square the circle, Mr Steinbrück intends to turn the federal corporate tax into a second trade tax.
Free-market conservatives hailed Ireland's rapid growth as an example of the miracles that free trade, tax cuts and deregulation can accomplish.
