A spurious correlation refers to a situation where:
A. two variables are related through their correlation with a third variable.
B. the correlation coefficient between two variables cannot be estimated.
C. there is direct causal relationship between two variables but tests for correlations reject this relationship.
D. the correlation between two variables is positive till the sample size reaches a threshold, and negative after the sample size crosses the threshold.
Answer: A
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Refer to Figure 4-14. To legally drive a taxicab in New York City, you must have a medallion issued by the city government. Assume that only 13,200 medallions have been issued
Let's also assume this puts an absolute limit on the number of taxi rides that can be supplied in New York City on any day, because no one breaks the law by driving a taxi without a medallion. Assume as well that each taxi provides 6 trips per day. In that case, the quantity of taxi rides supplied is 79,200 (or 6 rides per taxi × 13,200 taxis). This is shown in the diagram with a vertical line at this quantity. Assume that there are no government controls on the prices that drivers can charge for rides. a. What would the equilibrium price and quantity be in this market if there was no medallion requirement? b. If there was no medallion requirement, indicate the area that represents consumer surplus. c. If there was no medallion requirement, indicate the area that represents producer surplus. d. If there was no medallion requirement, indicate the area that represents economic surplus. e. What are the price and quantity with the medallion requirement? f. With a medallion requirement in place, what area represents consumer surplus? g. With a medallion requirement in place, what area represents producer surplus? h. With a medallion requirement in place, what area represents the deadweight loss? i. Based on your answers to parts (c) and (g), are taxicab drivers better off with the medallion requirement for taxicabs than without? j. Are consumers better off with or without the medallion requirement for taxicabs?
In a free market, a firm's rate of output is determined
a. where marginal social cost equals marginal social benefit b. where marginal private benefit equals marginal social benefit c. where marginal social cost equals marginal private cost d. where marginal private cost equals marginal private benefit e. by government