HDR: A large share of important economic interactions take place in a non-simultaneous fashion – i.e. one party takes an action in the expectation that another actor will behave as promised in the future. Such transactions occur between individuals, firms, and states. For these transactions to be undertaken, participants must believe that the counterparty will behave as promised – i.e. they need trust. The central question running through my work is “how should policy respond to a lack of trust?” Part of the answer to this question is clearly “build more trust”, and hence an important sub-theme of my work is examining which policies may be conducive to trustbuilding. In many circumstances, however, there are fundamental constraints on the extent to which parties may trust one another. In these cases the relevant question therefore becomes “how can policy mitigate the negative consequences of lack of trust?