An article in the Wall Street Journal notes that the average height in the United States has increased slowly in recent years, while the average height in the Netherlands has been increasing more steadily. Although for many years the average person in the United States was taller than the average person in the Netherlands, in 2019, the average person in the Netherlands was 2 inches taller than the average person in the United States. Income per person, or per capita, in the United States is 50 percent higher than income per person in the Netherlands. The article asks, “Why isn’t the U.S., with the highest disposable income per capita of any country, the world’s tallest nation?” Why might we expect a relationship between average income in a country and the average height of its residents? What might explain the difference between the average height in the United States and the average height in the Netherlands? Should policymakers be concerned about this difference? Briefly explain.