As you read in the textbook, economists tend to be critical of using emission standards as a policy instrument to control pollution on the grounds that it is not cost-effective. This argument is based on the fact that firms (pollution sources) differ on the pollution technologies they use, and a regulatory scheme that is based on emission standards does not account for this. Why should this problem not be resolved by firms adjusting thei technologies in response to the standards imposed by regulators? Is there some institutional barriers that stop this kind of adjustment from taking place? Discuss.