Compensation for Indirect Expropriation in International Investment Agreements: Implications of National Treatment and Rights to Invest

International investment agreements allow investors to bring compensation claims when their investments are hurt by new regulations. This requirement that host governments compensate for indirect expropriation helps solve post-investment moral hazard problems such as hold-ups, thereby helping to prevent inefficient over-regulation and encouraging foreign investment. However, when the social or environmental harm of a project is uncertain pre-investment, compensation requirements can interact with National Treatment clauses in a manner that reduces host government welfare and makes them less likely to admit investment. A police powers carve-out from the definition of compensable expropriation can be Pareto-improving and increase foreign investment.