What causes the tragedy of the commons? ( )
A. Social and private incentives differ.
B. Common goods are nonrival and nonexclusive.
Common goods are nonexclusive, but rival.
D. Both A and C are correct.
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A television signal is an example of ( )
A. a private good
B. a nonrival good.
C. a social good.
D. a normal good.
Most markets are not monopolies in the real world because ( )
A. firms usually face downward-sloping demand curves.
B. supply curves slope upward.
C. price is usually set equal to marginal cost by firms.
D. there are reasonable substitutes for most goods.
One of the defining characteristics of a perfectly competitive market is ( )
A. a small number of sellers.
B. a large number of buyers and a small number of sellers.
C. a standardized product.
D. significant advertising by firms to promote their products.
If all firms have the same costs of production, then in long-run equilibrium, ( )
A. price exceeds all firms’ average cost.
B. price exceeds all firms’ marginal cost.
C. some firms have positive profits.
D. all firms have zero profits and just cover their opportunity costs.
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