What do the United States, Liberia and Myanmar have in common?

Answer: They are the only three countries which have not officially adopted the metric system.

What about the US and Belize? They are the only two nations that use Fahrenheit instead of Celsius to measure temperature.

A daily hassle for an expat living and working in the US is dealing with the non-metric weight and measurement units, from foot, inch, yard, pound and ounce to gallon, quart, pint and Fahrenheit.

Watching the weather forecast in Fahrenheit only gives me a vague sense of how hot it is going to be. I'm not sure how much cheaper gas is in the US, since it is sold by the gallon, not the liter.

Since moving to New York 20 months ago, I have heard constant calls for changes, from tax, energy and immigration policy and social security to education, deficit reduction, government and military spending. "Change" was President Barack Obama's campaign slogan back in 2008.

Over the weekend, author and columnist Fareed Zakaria even suggested that changing from a presidential system to a parliamentary system would probably be a better idea for the US.

However, I haven't heard one voice calling for a complete change of the US customary units to the metric system now used by more than 95 percent of the world's population. That change seems no less important and urgent than any other changes hotly debated by American politicians and news media.

It is remarkable that the US, a founding member of the International Bureau of Weights and Measures in 1875, is still resisting the metric system.

Sticking to the traditional system has raised the cost for manufacturers and traders in the US and around the world since it requires them to design or label their goods using the specifications of the two systems. That is not helping Obama's ambitious goal of doubling US exports in five years.

It also reflects the fact that the US has not adapted to a new world. Its major trade partners, Canada, Japan, and Western Europe all switched to the metric system decades ago. China, now the US' second largest trade partner, adopted the metric system as early as 1925.

There is no doubt that switching to the decimal-based metric system will have numerous long-term benefits for the US despite some short-term costs. And it would make it more convenient for people to travel from within and outside the US. No doubt it would take some time for Americans to think in the new units, but compared to the other changes being talked about in the country this change could be more significant.

A complete conversion to the metric system would be a great moment to show the US' willingness to embrace the changes needed for the country and the world.

The US has been a leader of the world. It is now time for the US to show that it is also willing to follow the rest of the world by going metric.

The author, based in New York, is deputy editor of China Daily US edition. E-mail: chenweihua@chinadaily.com.cn

(China Daily 08/23/2011 page8)