Is it a good idea for the government to require automobile manufacturers to include pollution control devices, and certain safety devices (i.e. air...

If we look at this question through the lens of inequalities, we are likely to conclude that it is a good idea for the government to require these things.  This is because both pollution control devices and air bags prevent negative externalities.

Negative externalities are costs that are incurred when we use a product but which are not figured in to the price for which we buy the product.  Pollution is a prime example of...

If we look at this question through the lens of inequalities, we are likely to conclude that it is a good idea for the government to require these things.  This is because both pollution control devices and air bags prevent negative externalities.

Negative externalities are costs that are incurred when we use a product but which are not figured in to the price for which we buy the product.  Pollution is a prime example of this.  If you buy and drive a car, you contribute to pollution.  However, the cost of the car does not reflect the cost of cleaning up or otherwise coping with pollution.  Therefore, you are more likely to buy a car and drive it than you would be if you had to pay the whole cost, including costs related to pollution, of using the car. 

Similarly, injuries from car crashes are not factored into the price of a car.  When someone is injured in a crash, they tend to cost society money.  Society may have to help pay their doctor bills.  Their employers lose their services while they recover.  These sorts of costs can be prevented to some degree if the government requires safety devices in cars.

Thus, these things should be required from an economic point of view because they help to prevent negative externalities from occurring.