Final answer:
Tacit cooperation is more viable when there is a strong market share leader in an industry, a characteristic of an oligopoly market structure, rather than in perfectly competitive markets, heterogeneous industries, or those with low entry barriers.
Step-by-step explanation:
Tacit cooperation among firms in an industry is more likely to be a viable strategy when there is a strong market share leader. This situation implies some level of oligopoly, where a few firms dominate the market. In such scenarios, it may be easier for firms to align on output and pricing strategies to operate similarly to a monopoly, enhancing their profitability as opposed to operating in a perfectly competitive market where firms are price takers with no market control.
In contrast, a perfectly competitive industry with many sellers, easy entry and exit, identical products, and all participants being price takers would not facilitate tacit cooperation due to the competitive nature of the market and the inability of any single firm to influence pricing or output significantly. Similarly, heterogeneous industries with varied products and cost structures, as well as those with low entry barriers, would not sustain tacit cooperation easily due to the competitive pressures and the potential for new entrants disrupting any established understanding among current firms.