NEW YORK — America used to be the tallest country in the world.

From the days of the founding fathers right on through the industrial revolution and two world wars, Americans literally towered over other nations. In a land of boundless open spaces and limitless natural abundance, the young nation transformed its increasing wealth into human growth.

But just as it has in so many other arenas, America's predominance in height has faded. Americans reached a height plateau after World War II, gradually falling behind the rest of the world as it continued growing taller.

By the time the baby boomers reached adulthood in the 1960s, most northern and western European countries had caught up with and surpassed the United States. Young adults in Japan and other prosperous Asian countries now stand nearly as tall as Americans do.

Even residents of the formerly communist East Germany are taller than Americans today. In Holland, the tallest country in the world, the typical man now measures 6 feet, a good two inches more than his average American counterpart.

Compare that to 1850, when the situation was reversed. Not just the Dutch but all the nations of western Europe stood 2 1/2 inches shorter than their American brethren.

Does it really matter? Does being taller give the Dutch any advantage over say, the Chinese (men 5 feet, 4.9 inches; women 5 feet, 0.8 inches) or the Brazilians (men 5 feet, 6.5 inches; women 5 feet, 3 inches)?

Many economists would argue that it does matter, because height is correlated with numerous measures of a population's well-being. Tall people are healthier, wealthier and live longer than short people. Some researchers have even suggested that tall people are more intelligent.

It's not that being tall actually makes you smarter, richer or healthier. It's that the same things that make you tall — a nutritious diet, good prenatal care and a healthy childhood — also benefit you in those other ways.

That makes height a good indicator for economists who are interested in measuring how well a nation provides for its citizens during their prime growing years. With one simple, easily collected statistic, economists can essentially measure how well a society prepares its children for life.

"This is the part of the society that usually eludes economists, because economists are usually thinking about income. And this is the part of the society that doesn't earn an income," said John Komlos, an economic historian at the University of Munich who was born in Hungary, grew up in Chicago, and has spent the last quarter century compiling data on the heights of nations.

Height tells you about a segment of the population that is invisible to traditional economic statistics. Children don't have jobs or own houses. They don't buy durable goods, or invest in the stock market. But obviously, investments in their well-being are critical to a nation's economic future.