This paper describes a simple model of aggregate and firm growth based on the introduction of new goods. An incumbent firm can combine labor with blueprints for goods it already produces to develop new blueprints. Every worker in the economy is also a potential entrepreneur who can design a new...

In the data, a sizable fraction of price changes are temporary price reductions referred to as sales. Existing models include no role for sales. Hence, when confronted with data in which a large fraction of price changes are sales related, the models must either exclude sales from the data or...