Consider two ways of commuting in a crowded city: taking public transportation, such as subway and buses, or driving your own car. A person who chooses to take public transportation in a crowded city imposes a NEGATIVE OR POSITIVE externality on drivers. A policy implication of this result is a SUBSIDY FOR OR TAX ON those who take public transportation. Persons who choose to drive their own cars to get around in a crowded city impose a NEGATIVE OR POSITIVE externality on other drivers. A policy implication of this result is a TAX ON OR SUBSIDY FOR those who drive their own cars.

Answer and Explanation:

An individual who decides to take public transportation in a crowded city puts drivers on a POSITIVE externality. A policy implication of that outcome is a SUBSIDY for those taking public transport.

Many drivers are enforcing a NEGATIVE externality on people who want to drive their own cars to get around in a crowded city. A policy implication of that outcome is a TAX on those driving their own cars.

1) the stages a new product goes through from beginning to end, i.e., the stages that a product passes through from introduction through growth, maturity, and decline. 2) the time from initial research and development to the time at which sales and support of the product to customers are withdrawn. 3) the period of time during which a product can be produced and marketed profitably.

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