摘要:If agents learnbydoing and aremyopic, less advanced ¿rms might adopt new technologies while more advanced ¿rms stick with the old technology. This kind of overtaking can also occur if agents are forward looking and have high discount rates. However, overtaking never occurs if agents are suf¿ciently patient. A ¿nite discount rate increases the set of states at which agents adopt new technologies, so more patient agents tend to upgrade their technology more frequently.