US agriculture shifts focus from land to materials, boosting productivity gains.
A study on U.S. agricultural production used a new method to analyze data and found that over time, output in the U.S. became more responsive to changes in materials and less responsive to changes in land and labor. The study also showed that productivity gains increased slightly in the 1960s and 1970s, slowed down in the 1980s and 1990s, and stabilized afterwards. All inputs in production are substitutes, and their elasticities of substitution have increased over the decades.