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.
On the education path, a Masters degree might come before a PhD, but the PhD is a higher academic award. Students do not always have to follow the path, but typically the Bachelors degree is a 'first' degree, the Masters is a second degree, and a Doctorate degree such as the Doctor of Philosophy (PhD) is a terminal degree. A graduate degree requires a significant investment of time.