What will increase the likelihood that the firms in an industry will conclude to maximize their joint profit?

Step 1: Analyze the question The question asks what makes it more likely that firms in an industry will collude (cooperate, as in a cartel) to maximize their joint profit.

Step 2: The concept Collusion works best when:

• There are few firms, so agreements are easy to reach and monitor.
• Products are similar (homogeneous), so prices are easy to coordinate.
• Entry is difficult, so new competitors cannot undercut the agreed price and erode the extra profits.
• The market conditions are stable.

Step 3: Check each option

• A. Many differentiated products: Differentiation makes it hard to agree on common prices and output, so collusion is less likely. ✗
• B. Rapid technological change: This makes the market unstable and gives firms an incentive to break agreements and innovate. ✗
• C. Large number of producers: Many firms make coordination and policing difficult, and cheating is more likely. ✗
• D. Significant barriers to entry: These protect the colluding firms from new entrants. The high joint profits stay in the industry, so the agreement is sustainable. ✓

Step 4: Answer The correct option is D.

Tip: Remember the phrase "Few, Similar, Protected." Collusion thrives with few firms, similar products, and protection from new entrants (barriers to entry). Think of OPEC as a real-life cartel example: a small group of producers selling a similar product, with high barriers to entering the oil industry.