The U.S. uses the metric system and the customary system.
Even many countries that are primarily metric use non-metric units like stones for body weight or feet for airplane elevation.
I agree that metric would be a better system, but your implication that we can't compete in the global economy with our mixed unit system seems hyperbolic since we have already been competing just fine.
Haha what? No one using the metric system uses "stone" for body weight. They use kilos.
Even the US doesn't use "stone" - you use pounds, which is your stand-in for the kilogram.
EDIT: Seriously, I cannot think of a single country which uses "stone" for bodyweight. Maybe the British? But doctors don't, definitely not in Australia, and I've never heard anyone from any other places use it either.
Not sure why you're getting downvoted. Where I'm from, nobody uses stones, a few people use catty (http://en.wikipedia.org/wiki/Catty), some people use pounds, most people use kilos.
My comment was about the bad map. The map makes it seem like metric is a binary condition: you use it or you don't. That is not true, even though metric is the primary measurement system in most of the world. Many non metric units are in common use in primarily metric countries, just like the U.S. doesn't only use customary units.
The UK should also be highlighted on the map since they use stone and pints, as well as Canada and apparently Singapore and other countries in southeast Asia that use other units like catty and pounds. That Singapore or Australia don't use stone doesn't disprove my point in the slightest. I am just listing examples of non metric units in active use, in countries that the map claims use metric.
In practice there are still some throw backs (pints of milk or beer) except that EU directives mean that the 4 pint milk container has to be labelled 2.27 litres, etc..
Switching my mental model of pricing of fruit was quite hard but it's really annoying now that supermarkets still list imperial prices alongside (and occasionally in breech of regulations, alone). Metric prices are larger numbers and they want to convince us they're not overcharging. Unfortunately my regular supermarket have taken to pricing by the item or bag for fruit - causes no end of problems, all the bags are different weights. More expensive items in 800g bags (or 750g), less expensive in 900g or 1kg. Good for keeping my mental arithmetic going though - which is cheaper those apples for £1.20 a bag on 3-for-2 or these for 40p each with a coupon for 10% off ...! /rant
Even many countries that are primarily metric use non-metric units like stones for body weight or feet for airplane elevation.
I agree that metric would be a better system, but your implication that we can't compete in the global economy with our mixed unit system seems hyperbolic since we have already been competing just fine.