Risk sharing, risk shifting and the role of convertible debt

This paper considers a financial contracting problem between a risk neutral entrepreneur and a risk averse investor. Once the venture is started, the entrepreneur chooses an action that determines the riskiness of the venture's payoff. When action choice is contractible, the optimal risk sharing consideration under limited liability calls for a pure debt contract and the low risk action is adopted. When the action choice is not contractible, due to the risk shifting problem implementing the low risk action requires a deviation from the optimal risk sharing. I focus on situations where despite this deviation, the risk averse investor prefers to implement the low risk action and show that a convertible debt contract is superior to pure debt, pure equity and any mixture of debt and equity.