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.
PhD and MPhil research degrees allow you to undertake in-depth study in a specific area. PhD is either 3 or 4 years duration, depending on your background and the project outline. There is also the possibility of initial laboratory rotations, for example as part of the Wellcome Trust 4 year PhD.