Market Quality, The Big Picture
JAMES ANGEL: The problem with a precise definition is that market quality means different things to different people. Sometimes we look at cost. Sometimes we look at liquidity. For most, market quality is kind of like the distinction between art and pornography: we know the difference when we see it. A cost to one party is revenue to another. The optimal cost is not necessarily zero to the extent that the other party is providing some services for that revenue.