Planned obsolescence works when company selling the product has few or no other companies making the same product, because the consumer has few choices. Before choosing this strategy, the producer has to make sure that the consumer will likely buy from them again and not from someone else. Usually, there is information asymmetry: the producer knows how long the product was designed to last, and the consumer does not. However, when many companies make the same product, they compete. Then product lifespans often increase. In the 1960s and 1970s, the first Japanese cars were sold in America. Because they had longer lifespans than the American car models, American car manufacturers were forced to build cars that lasted longer.