The article explores economic situations with incomplete contracts. It looks at inefficient monopolies selling durable goods, downstream mergers affecting producers' capacity choices, and contract bargaining with multiple agents. The researchers found that in monopolies, some buyers make random purchase decisions to benefit from low prices, leading to inefficiency. Downstream mergers can either increase or decrease a producer's capacity depending on the cost. In contract bargaining, equilibria payoffs align with the Shapley value, which can result in either efficient or inefficient outcomes based on information and agents' beliefs.