For an individual who has special talent as an entertainer, a large proportion of his salary can be considered

Economic theory asserts that:

a. both implicit costs and explicit costs are relevant in decision making. b. only implicit costs are relevant in decision making. c. only explicit costs are relevant in decision making. d. a cost to be incurred in the future should count more heavily than a cost incurred today

The percentage of all sales contributed by the leading four or leading eight firms in an industry is known as

A) a horizontal merger. B) a vertical merger. C) economies to scale. D) the concentration ratio.