Behold, I bring you good tidings of great joy which shall be to all people: as of today, there are eight billion of us. Contrary to what the environmental movement tells us, that eight billionth person is a blessing, not a curse.

We should be celebrating. Person number eight billion brought another mouth to feed, it’s true, but she also arrived with nimble hands and, most importantly, one of those wonderful little idea factories that we call a brain.

In the very short run, our eight billionth neighbor puts at least some pressure on our stock of proved resources. By buying her diapers, her parents are calling resources like adhesives and polymers out of other uses. Prices rise just a little. In the long run, however, necessity is the mother of invention. People find new, innovative ways to economize on the resources we know about, and they find new, innovative ways to find new resources.

This is what the economist Julian Simon thought, and more importantly, it’s what he demonstrated in a body of research that, in my opinion, should have won him a Nobel Prize. The human mind, Simon argued, is The Ultimate Resource, and when people are free to invent, innovate, and try new things, they create new possibilities.

As my friend and coauthor Deirdre McCloskey as put it, every new product—and every new resource—begins as an idea. More people means more brains. More brains means more ideas. As McCloskey and I argue in our book Leave Me Alone and I’ll Make You Rich: How the Bourgeois Deal Enriched the World (which I discuss here and here, and which is available in paperback this month), economic liberty and social dignity for innovators and entrepreneurs put those minds to work and led to the cornucopia we enjoy today.

Simon demonstrated this by looking at the data. He showed that in the long run, resource prices tended to fall. This is consistent with his thesis that more brains are a blessing, and it flatly contradicts the popular-but-wrong idea that there are too many people and that we have exceeded the world’s carrying capacity. Others have followed in Simon’s footsteps and expanded on his argument. Just one contribution to this tradition is Superabundance: The Story of Population Growth, Innovation, and Human Flourishing on an Infinitely Bountiful Planet by Marian L. Tupy and Gale L. Pooley. I reviewed it for the American Institute for Economic Research, and it’s a book everyone should have on their bookshelf—or as I do, in their Kindle library.

Today marks a momentous occasion that should be cause for dancing, not mourning. We should welcome our new neighbors, not reject them or worry that they’ll somehow leave us worse off. If we embrace creativity and innovation, like Julian Simon suggests, every new person is a small step toward a better and brighter future for all of us.