Dividing the revenue of each competitor by the total market size will calculate the market share

Economists refer to knowledge "spillovers" as externalities, and there is a well-established theory suggesting that firms can benefit from such externalities by locating close to their source

Indicate whether the statement is true or false.

Which of the following is untrue regarding the contracts of incompetent persons?

a. An incompetent person is liable for necessaries. b. Unlike a minor, an incompetent person can never ratify a contract. c. To avoid a contract, a person need not be permanently incompetent. d. Under the cognitive ability test, a person is incompetent if he is unable to understand the nature and effect of his act.