Moreover, several empirical studies have found that economic instruments such as water pricing or tradable water rights offer a more cost-effective water management strategy than command-and-control policies, thanks to the heterogeneous nature of users’ marginal benefits from water consumption (Olmstead and Stavins, 2009). The overall equity implications of economic instruments depend on their precise design: whether the water-pricing scheme is linear or block-rate (see Chapter 2 for a more detailed discussion of equity in water tariffs); how water rights are initially allocated; whether water trading may refrain low-income farmers from receiving enough water to sustain their livelihoods in water-stressed regions, etc. They should therefore be considered when determining how to promote the acceptability and long-term stability of the reforms.