It's the Simple Things That Count: Like Concrete

  Charles Kenny writes:

Starting in 2000, a program in Mexico's Coahuila state called "Piso Firme" (Firm Floor) offered up to $150 per home in mixed concrete, delivered directly to families who used it to cover their dirt floors. Scholar Paul Gertler evaluated the impact: Kids in houses that moved from all-dirt to all-concrete floors saw parasitic infestation rates drop 78 percent; the number of children who had diarrhea in any given month dropped by half; anemia fell more than four-fifths; and scores on cognitive tests went up by more than a third. (Perhaps unsurprisingly, mothers in newly cemented houses reported less depression and greater life satisfaction.)

 Concrete also works for highways, which improves economies in the third world.