Robert Woodberry says you can actually quantify how Christian missionaries changed the world.
Missionaries have profoundly shaped the world in all kinds of outcomes. They introduced lots of new crops; they introduced the idea that everyone should be able to read – particularly Protestant missionaries – that everyone should have access to texts; they introduced printing all around the world, or where printing existed already they turned it into mass printing; they introduced newspapers; they introduced modern Western healthcare. They introduced all kinds of things, and when other people were not doing that. And not only directly, but through the people that they trained and through the competition that they spurred, they had a profound influence on people’s health, on people’s education, on the accessibility of books. And then that has had both economic and political outcomes.
So, for example, you can explain about 14 percent of the variation in current GDP, economic development, based on the historical prevalence of Protestant missionaries. You can explain about half the variation in current political democracy based on the historical prevalence of Protestant missionaries. I mean these effects are huge, they’re quite huge.