For others Washington raises prices directly by limiting both production and imports.
However males are rare, which limits commercial production of this fish.
The factors limiting primary production in the ocean are also very different from those on land.
The increased life cycle of products like cars and computers means lower demand, so companies need to limit production.
It costs millions of dollars and often several years to register a pesticide, which limits production only to large players.
The government was trying to limit production because of economic and environmental concerns.
Oil analysts see the agreement as more credible than previous efforts to limit production.
They would be happy to sell more of it, but they agreed long ago that the only way to control quality was to limit production.
Animosities within the organization have reduced its 13 members' ability to reach an agreement to limit production.
It also plans to limit production of new models.