The United States is the world’s largest economy. Yet, in the last two decades, like in the case of many other developed nations, its growth rates have been decreasing. If in the 50’s and 60’s the average growth rate was above 4 percent, in the 70’s and 80’s dropped to around 3 percent. In the last ten years, the average rate has been below 2 percent and since the second quarter of 2000 has never reached the 5 percent level.