Amy must decide whether or not to make an investment that costs 1. The investment pays a return of 5, but is risky to Amy because Bill must be given charge of the asset if it is to be productive. If Amy invests, then Bill must decide whether to keep the entire return for himself, or to split the return, giving 3 to Amy and keeping 2 for himself. (Amy pays the cost 1 even if Bill does not pay her back.) If Amy does not invest, then both players get 0. This is called a trust game because Amy wants to invest only if she trusts Bill to pay her back.
(a) Model this as an extensive-form game
(b) What is the strategic-form corresponding to your extensive-form?
(c) Find all of the Nash equilibria. Which are the subgame-perfect?