Suppose that Lionel Messi is negotiating a contract with FC Barcelona. Messi has an offer from Real Madrid for $20 million a year. If he signs with FC Barcelona, they will earn $90 million in revenue from the signing. FC Barcelona's next best option is to sign Cristiano Ronaldo. They would earn $70 million from signing Ronaldo and would pay him a contract of $10 million. Messi's bargaining power is w = 1/2.

a) What is the negotiated salary between Messi and FC Barcelona under Nash Bargaining? What is Messi's surplus and what is FC Barcelona's surplus?

b) Due to an injury, FC Barcelona would only earn $50 million from signing Ronaldo but everything else remains the same. What is the negotiated salary between Messi and FC Barcelona under Nash Bargaining? What is Messi's surplus and what is FC Barcelona's surplus?