The U.S. Department of Agriculture's (USDA) Economic Research Service (ERS) regularly compiles and publishes total factor productivity indexes for the aggregate farm sector. These statistics make clear that productivity growth is the single, dominant source of economic growth in the sector. However, the consistently high rates of productivity growth reported for the aggregate farm sector conceal significant variations in regional and State trends. 'Productivity growth within States and regions deviates significantly from the sector average. Moreover, intertemporal shifts in State productivity growth rates express far more volatility than is revealed by examining average nationwide patterns.