Supply and demand curves continue to work even in the face of government intervention. There are several permutations to consider, and in every one there are large side-effects from fighting economics.

Which is not to say that it is not worthwhile from time to time. For instance virtually every country today accepts that it is worth intervening in agriculture. However it is not nearly as simple as declaring a new price by fiat and seeing the world accept that.

Cheers,
Ben