(NAFB) – Agricultural output in the United States nearly tripled between 1948 and 2017 even as the amount of labor hours-worked declined by more than 80 percent.

USDA’s Economic Research Service says the opposing trends resulted in an increase in labor productivity growth in the U.S. farm sector. Labor productivity, calculated as average output per unit of labor input, is a popular measure for understanding economic growth.

ERS estimates agricultural output per worker grew by 16 times from 1948 through 2017. At the same time, agricultural output per hour worked grew even faster, by 17 times, implying that average hours worked per worker declined. Labor productivity estimates can vary based on different ways labor is measured. One factor in the increased labor productivity is the quality of labor, measured by attributes such as age, gender, and the highest level of education a worker has reached.

ERS researchers estimate that changes to farmworker attributes accounted for about 13 percent of growth in hourly-based annual labor productivity during the time studied.