Editor’s Note: Steven Murphy is the founder of Murphy & Partners, a specialist arts advisory firm. Prior to founding his firm, Murphy was chief executive of Christie’s International. This story is part of a series of videos answering some of the most popular questions about the art world.

CNN  — 

Ever wondered how art prices are set? Or, what makes one piece of art more expensive than another? In the short video above, the former CEO of Christie’s International and expert art adviser Steven Murphy explains how art is valued and how sale prices are agreed.