The standard treatment of U.S. agriculture asserts that, before the 1930s, productivity growth was almost exclusively the result of mechanization rather than biological innovations. This paper shows that, to the contrary, U.S. wheat production witnessed a biological revolution during the 19th...

The standard treatment of U.S. agriculture asserts that, before the 1930s, productivity growth was almost exclusively the result of mechanization rather than biological innovations. This paper shows that, to the contrary, U.S. wheat production witnessed a biological revolution during the 19th...