Appraising oligopoly.
wWhy do we like perfect competition?
nThe last unit of output is earning exactly the opportunity cost of the resources that went into it.
nStatic resource allocation.
"The problem of economics may, as it seems to me, be stated thus: -- Given, a certain population, with various needs and powers of production, in possession of certain lands and other sources of material: required, the mode of employing their labour which will maximize the utility of the produce."  (Theory of Political Economy, 4th ed., p. 267.)
wBut is that all we might ask for in appraising industry structure?
William Stanley Jevons, 1835-1882