1. The current population of the United States is 331.4 million with 2.0% of the population is engaged in R&D at an efciency rate of 1/400 per million persons per year. (a) If R&D is the only source of totalfactor productivity growth what is the growth rate of labor eiciency in the United States? (b) If the growth rate of total factor productivity is 0.8% per year, what is the value of o: in the CobbDouglas production function