Your friend has a large garden and grows fresh fruit and vegetables to be sold at a local farmer’s market. Your friend comments, “I hired a college student who was on summer vacation to help me this summer and my production more than doubled. Next summer, I think I’ll hire two or maybe three helpers and my output should go up more than three or fourfold.”
If all production process eventually exhibit diminishing marginal product of the variable inputs, could it be true that your friend hired a helper (doubled the labor) and more than doubled his production? Why or why not? By the way, in the long run, what must your friend do to the scale of his operation if he/she wants to continue to hire workers and have those workers generate proportional increases in production? Even in the long run, could your friend expand the scale of operation forever and continue to keep average costs at a minimum?