we did not get really good control over the techniques for purifying drinking water until about World War I, but we needed everything that was done up to that point to figure out how to do it. Then there was a diffusion process. Some cities implemented systems quickly but others didn’t because it was very costly.
...In 1900, about a third of cows in the United States had bovine tuberculosis. Even when dairies started to pasteurize the milk, it wasn’t very effective. There were a lot of contaminants that made it into the milk. So we probably didn’t get a safe milk supply until the 1930s.
The wide-ranging interview also includes Fogel's forecast for higher growth in China than in India.
There are too many people
in India — some call them “rural romantics” — who would be willing to pay a price of two or three points in the growth rate in order to preserve certain traditional values. Also, there are more ethnic minorities in India than there are in China.