World Population Growth

Not only was October 31, 2011 a day when we ate exorbitant amounts of candy and wore silly costumes, but it was also a day when the world population reached a whopping 7 billion people. While a "Gross World Product" is not something we currently measure, I wonder what effects the world's ever-growing population could have on worldwide production. We mentioned that in the Cobb-Douglas model, the growth rate of output could be increased by either changes in efficiencies or changes in capital and labor. But in today's world, not every person who is eligible to be in the work force contributes to the production of goods. It could be the case that large working-age populations have negative effects on an economy. Contrary to what the Cobb-Douglas production function might suggest, the growth rate of labor might have a negative relationship with the growth rate of output. A high labor growth rate might not be so good for the world economy after all.