Consider an exchange economy with two consumers, Ivan and Kay, and two goods, tacos (t) and donuts (d). Their well-behaved preferences are represented by uI = 2 ln tI + 3 ln dI and uK = 3 ln tK + ln dK. All the conditions for the first and second theorems of welfare economics to apply are met. Ivan's endowment is 4 tacos and 7 donuts; Kay's endowment is 1 taco and 1 donut.

a) Find an equation for the contract curve in this economy. What is the contract curve?

b) Consider an allocation in which Ivan gets 2 tacos and 6 donuts and Kay gets 3 tacos and 2 donuts. Can this allocation be supported as a competitive equilibrium? If so, how, and what would the price ratio be in that equilibrium? If not, why not?