The difference between living standards of the rich and poor within a region was not as great as that between regions across the world.

The within-region and between-region differences in living standards were similar in the pre-17th century and post-17 century.

The difference between living standards of the rich and poor within a region was almost same as that between regions across the world.

The within-region differences in living standards was larger than between-region differences in living standards.

The APL is the slope of the tangent line.

The APL at 0 hours is 20.

The APL is decreasing beyond 15 hours of study.

The APL at 10 hours is 3.

The total compensation paid will be £6,400.

The nurses are worse off than they would be under the Pigouvian tax.

The factory’s profit would be the same as under the Pigouvian tax.

The factory’s marginal private cost now equals the marginal social cost.

At Q = 80, both the factory and the nurses would benefit from the factory paying a fee less than 80 to the nurses to increase output.

The efficient level of output is the factory’s profit-maximising quantity, which is 120.

The efficient level of output is 0, where there is zero marginal external cost to the nurses.

At Q = 120, both the factory and the nurses would benefit from the nurses paying a fee less than 120 to the factory to reduce output.

The total compensation paid will be £6,400.

The nurses are worse off than they would be under the Pigouvian tax.

The factory’s profit would be the same as under the Pigouvian tax.

The factory’s marginal private cost now equals the marginal social cost.

At Q = 80, both the factory and the nurses would benefit from the factory paying a fee less than 80 to the nurses to increase output.

The efficient level of output is the factory’s profit-maximising quantity, which is 120.

The efficient level of output is 0, where there is zero marginal external cost to the nurses.

At Q = 120, both the factory and the nurses would benefit from the nurses paying a fee less than 120 to the factory to reduce output.

A tax to impose a socially optimal level of pollution would add to the firm’s average costs of production an amount equal to the cost imposed on everyone affected.

To achieve the socially desirable level of pollution, it will always be more efficient to impose a tax per unit of pollution than to regulate the quantity of pollution emitted by each firm.

If the government regulates an industry consisting of two firms using a cap-and-trade scheme and distributes pollution permits equally between them, the one which finds abatement less costly will sell pollution permits to the other firm.

The total compensation paid will be £6,400.

The nurses are worse off than they would be under the Pigouvian tax.

The factory’s profit would be the same as under the Pigouvian tax.

The factory’s marginal private cost now equals the marginal social cost.