Does it matter? Economists think so because height correlates with a population's well being.
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.Lots more here.
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.