More than 20 years after it was abolished, Margaret Thatcher's poll tax remains the locus classicus for domestic political miscalculation and the yardstick by which all other UK governmental policy ineptitudes are still judged.
The real yardstick for the chancellors' debate, therefore, is whether the public's views about Alistair Darling, George Osborne or Vince Cable have changed at all tonight.
It is inflation as measured by the producer prices index, as measured by the personal consumer expenditure deflator (the yardstick of choice for the Fed), as measured by the monthly survey of small businesses, and as measured by the Institute of Supply Management.
The results highlighted the inadequacy of using the global mean surface temperature as the primary yardstick for climate change.
For Mr Sharon, the yardstick is whether Mr Arafat will end Palestinian violence and incitement and, in the words of Mr Powell's speech, "arrest, prosecute and punish the perpetrators of terrorist acts", as a precondition to Israel's ending its violence against Palestinians.
No other country offers such a perfect yardstick for comparison, involving near-identical levels of national wealth, population, military clout, diplomatic cunning and historical swagger.
This would reduce the incentives for other regional powers, such as Saudi Arabia and Egypt, to move towards the nuclear threshold themselves.The yardstick is Iran's "breakout capability"—the time it would take to produce enough weapons-grade uranium for one device.
Other countries in the hemisphere, and beyond, will look to progress on NAFTA as a yardstick of what they can expect under the FTAA and in the WTO.
But one can use a rough-and-ready yardstick: in how many places did the inventors seek a patent for the same technology?
The difficulty is partly that there is no single yardstick for measuring progress in those areas.
Richard Strauss called for "lots of horns, which are always a yardstick for heroism".
