6. (12 points) Industry A produces a product that everyone needs as well as a great deal of pollution. Suppose that many identical countries have firms in industry A. The pollution can be controlled using alternative production techniques, but this raises the marginal cost of production. (a) (3 points) If the pollution created by the industry is primarily local, is an international agree- ment necessary? Now suppose that the pollution created is global. (b) (3 points) If all countries require the industry to use the low pollution production technique, what happens to the price on world markets