DUOPOLY WITH
FIRM 1 AND 2 TAKE SIMULTANEOUS DECISIONS ABOUT THIR PRICE BASED ON THE EXPECTATION ABOUT THE PRICE OF THE OTHER FIRM
FIRMS' DECISIONS ARE BEST REPLIES
PREDICTIONS ARE FULFILLED
IN EQUILIBRIUM PRICE IS HOMOGENEOUS AND MUST BE EQUAL TO MARGINAL COST
FIRM 1 IS QUANTITY LEADER
LEADER'S OUTPUT = MONOPOLY OUTPUT ournot
OF
IN AN IDEAL WORLD, WE SHOULD HAVE THAT
IN REAL WORLD
BECAUSE PREFERENCES ARE PRIVATE INFORMATION
OF 1
WEALTH OF AGENT 2
THE ABOVE INEQUALITIES IMPLY THAT:
= CONTRIBUTION PER UNIT OF G
= CONTRIBUTION PER UNIT OF G
IN PARTICULAR,
|MRS| = MARGINAL WILLINGNESS TO PAY FOR 1 ADDITIONAL UNIT OF THE PUBLIC GOOD G, IN TERMS OF GOOD x
TO MAKE THE SUPPLY G > 0 PARETO EFFICIENT