Final answer:
In the model of perfectly competitive firms, businesses that consistently cannot make money will fail and cease to exist. This can occur due to various reasons such as old technology, poor management, shifting consumer preferences, or competition.
Step-by-step explanation:
In the model of perfectly competitive firms, those that consistently cannot make money will "exit," which means they will fail and cease to exist. This can happen for a variety of reasons such as old technology, poor management, shifts in consumer tastes, or strong competition. According to the U.S. Small Business Administration, many businesses fail each year, with the number of business exits being higher than the number of new business entries.