Fifty Inventions That Shaped the Modern Economy

by Tim Harford

Piso Firme means “firm floor,” and when economists studied the program they found that the ready-mixed concrete dramatically improved children’s education. How so? Previously, most house floors were made of dirt. Parasitic worms thrive in dirt, spreading diseases that stunt kids’ growth and make them sick. Concrete floors are much easier to keep clean: so the kids were healthier, they went to school more regularly, and their test scores improved. Living on a dirt floor is unpleasant in many other ways: economists also found that parents in the program’s households became happier, less stressed, and less prone to depression when they lived in houses with concrete floors. That seems to be $150 well spent.