Corporations own a very small percentage of business assets. The federal government receives most of its revenue from personal income taxes and payroll taxes. A well-functioning market will have high monetary costs applied to high opportunity costs. Given its size, the United States does not have to worry about limitations on resources. Efficiency is defined as the absence of waste.
Division of labor allows individual workers more ability to perform a job.
Demand shifts due to a change in price. Consumer income changes can shift market demand. Supply will shift for any reason other than a change in the price of the good.