To retain its economic power, America needs more people.

For over a century, the United States has been the world’s economic kingpin. By the time World War I was declared, its per-person income had overtaken the British Empire’s. And by 1938, America’s gross domestic product, or GDP, was greater than that of Germany, Japan, and Italy combined. This economic strength meant the US had superior wartime resources, and its soldiers were better equipped, both to fight and to stay healthy. And this helped America to win wars and conquer its enemies.

But the United States’ economic stronghold is being threatened by rising wealth in China. Americans are currently four times wealthier than Chinese people. But the gap between each country’s GDP is shrinking. China has over one billion people; the US has just 330 million. And if the Chinese population became just half as wealthy as Americans, China would become the world’s top economy. This is set to happen within the next 20 years.

The key message here is: To retain its economic power, America needs more people.

Many people assume that a large population leads to poverty. And this was true before the Industrial Revolution. But, today, a higher population helps our modern economy thrive. More people need more services, which means more business transactions. So, increasing America’s population would stimulate the economy, generating more wealth for the country. Tripling it to one billion people would help America retain its economic power.

A country the size of the US could comfortably accommodate a billion people. There are currently 93 people per square mile. Even if this figure were tripled, the number of people per square mile would still be considerably lower than in developed countries like Singapore, South Korea and even Belgium.

At one billion people, the US would be about as densely populated as France. If you visit the land of baguettes and fromage, you probably won’t feel overwhelmed by locals unless you’re on the Metro during rush hour. And even then, the density is nothing like what you’d find in the United Kingdom or Italy.

Of course, increasing a country’s population dramatically has ramifications, from housing shortages to environmental impact. But with the right policies in place, the government could overcome these challenges. In the blinks ahead, we’ll explore what would need to change for a billion-person US to work, and how America would benefit from tripling its population.