3. Consider a public good problem where two players, 1 and 2, contribute simultaneously x 2 0 and y 2 0. Then the payoff for each player is then: For player 1. f (x, y) = [A .(xty)-x if xtysl, 1-x if xty>1. For player 2, f (x. y) = [2-(xty)-y ifxtysl, if xty>1. Assume that 1 = 3/4. (a) Suppose this game is played twice (with no discounting). Find all Subgame Perfect Equilibria. (b) Suppose that the above game is played infinitely many times (with payoffs discounted by the discount factor of 6 e [0,1) ). Construct the Subgame Perfect equilibrium strategies of the resulting repeated game that will sustain x = y = - in every period for a 2 sufficiently large 6 . What is the minimal value of 6 = [0,1) necessary for this result