New car fleet fuel economy, weight and engine power have changed drastically since 1980. These changes represent both movements along and shifts in the "fuel economy/weight/engine power production possibilities frontier." This paper estimates the technological progress that has occurred since...

Incompatibility in markets with network effects can either benefit orharm consumers. Incompatibility reduces consumers' ability to "mixand match" components offered by different sellers, but can also beassociated with changes in product attributes that might benefitconsumers. In this paper, we...