One of the harmful emissions from coal-burning electric power plants is sulfur. Enacted environmental regulations require adding "scrubbers" to exhaust stacks to reduce emissions such as sulfur but this is very expensive. Some have suggested that instead of scrubbers, sulfur emissions should be taxed. As shown in the table below, one study estimated effects of different per unit sulfur taxes.

	$0.00 per lb	$0.05 per lb	$0.10 per lb	$0.15 per lb	$0.20 per lb
Emissions (millions of tons)	11.4	10.0	8.25	7.5	6.7
Coal production (millions of tons)	507	492	459	450	427
Total Cost of Energy (billions)	5.11	5.67	6.92	7.25	8.10
Marginal Cost of Energy (billions) [Note: this is the MC of abatement]
Total Environmental Damage (billions)
Marginal Environmental Damage (billions) [The Marginal Benefit of Abatement]

1. Complete the marginal cost of abatement row treating each column as a one-unit increase. Show all work. [Hints: i) recall from Module 7 how to calculate marginal cost by subtracting values given in the table ii) all numbers should be positive]
2. Now, assume the total damage to the environment is estimated to be $756 per ton of sulfur emitted. Use this and the information in the table above to find the total environmental damage for each level of emissions (11.4 million tons, 10 million tons, etc.). Show all work in addition to filling in the table cells.
3. Next, calculate the marginal environmental damage (the marginal benefit of abatement) and add these to the table (show all work). [Hint: again, numbers will be positive]
4. Examine the results in the table and recommend the most efficient sulfur tax rate. Explain your choice.