LIP is a method of calculating the marginal price for energy and/or transmission at points in the road (known as nodes) on the grid reflecting transmission loading problems. The Federal Energy Regulatory Commission (FERC) has proposed LIP as a way to achieve short- and long-term efficiency in wholesale electricity markets. This is similar to the current practice of calculation in economic dispatch for each utility as well as avoided costs for Qualifying Facilities (QF) under Public Utility Regulatory Policy Act of 1978 (PURPA).