For instance, low rates and lax enforcement (e.g. illegal abstractions, underreporting of consumption) prevent abstraction charges from being effective instruments for water policies, while low pollution charges do not significantly change the behaviour of polluters. Water markets are a step in the right direction, but they tend to be poorly designed and can lead to over-abstraction. Payment for ecosystem services (PES) schemes are in place and the Pact recently adopted by the new Mexican administration explicitly requests that they be strengthened (commitment 66).