1. Producer Theory 1. Technology yi =input of good i, y =output of good i, i= yi-yi=net output, y yn) is a production plan Production possibility set Y=technologically feasible production plans yE Rn) y E Y is technologically efficient if there is no yE Y s.t. y>y

Corporate finance 1. Theoretical Approaches 1.1. Corporate Finance in Arrow-Debreu world Complete market, perfect market, perfect competition, symmetric information, private consumption Risk: risk sharing, risk pooling, technology shocks, individual vs aggregate shocks Lucas(1978): existence of equilibrium asset price Merton: continuous-time pricing model

Problem set 3 Micro Susen Wang Try to do most problems in MWG(1995), Chapters 7-9 Question 3.1.(Mixed-Strategy Nash Equilibrium). A principal hires an agent to perform some service at a price(which is supposed to equal the cost of the service The principal and the agent have initial

Problem set 2 Micro Theory S. Wang Question 2. 1. You have just been asked to run a company that has two factories produc ing the same good and sells its output in a perfectly competitive market. The production

Problem set 1 Micro Theory S. Wang Question1.1. Show that“f(X)=f(x),Vx∈R,A>1” implies“f(A)= Af(x),Vx∈R,A>0.” estion 1.2. Use a Lagrange function to solve c(w1, w2, y) for the following problem

8.1. Independent Firms The downstream firm's problem is max(a-bxc-wT The upstream firm's problem is max(a-2b)3-cr The output is 8.2. Integrated Firm Suppose now that the two firms merge into one firm. This firms problem is max(a-by)y

Then =1-91=1(3+:2)(3+2n 可=-1-3)=1(4-+2)(1-2+a With 1 0 O: Thus, in equilibrium, we must have ai=.2. In fact, the two firms must sit in the middle By Proposition 2.1, Pi=p?=c Discussion

5. Oligopoly Oligopoly: Small number of firms: Firms depend on each other. Identical products: Firms jointly face a downward sloping industry demand No entry: Long-run positive profits are possible

This formula applies to any type of firms in the output market 1. Competitive Output Market Competitive industry: Many firms: Firms are independent of each other in decision making Identical product: Each firm faces a horizontal demand curve at the market price Free entry: Zero profit in the long run A competitive firm takes the market price as given. For a given market price p

Social welfare function W: Rn-R gives social utility W(u1, u2,. un ). W is strictly increasing is socially optimal if it solves max Wu(a1), u2(a2),., un(n) st>Tis>w Proposition 1.29. If is SO, it is PO. I Proposition 1. 30. Suppose that preferences are continuous, strictly monotonic, and strictly convex. Then, for any PO allocation x* with >>0,v i, there exist ai