Long-Run Average Total Cost-LRATC. Firms examining the long run understand that they cannot alter levels of production in order to reach an equilibrium between supply and demand.ong-Run Average Total Cost-LRATC. Firms examining the long run understand that they cannot alter levels of production in order to reach an equilibrium between supply and demand.
PhD is short for Doctor of Philosophy (also abbreviated to DPhil or Dr.Philos). This is an academic or professional degree that, in most countries, qualifies the degree holder to teach their chosen subject at university level or to work in a specialized position in their chosen field.
In the United States, the Ph.D. degree is the highest academic degree awarded by universities in most fields of study. U.S. students typically undergo a series of three phases in the course of their work toward the Ph.D. degree.