Which of the following factors make it more likely that

oligopolists will play noncooperatively? Which make it more

likely that they will engage in tacit collusion? Explain.

a. Each oligopolist expects several new firms to enter the

market in the future.

b. It is very difficult for a firm to detect whether another firm

has raised output.

c. The firms have coexisted while maintaining high prices for a

long time.