Consider a two-product firm that decides on the quality of each product. Product quality is unknown to consumers. If the firm sells both products under the same brand name, consumers adjust their beliefs about quality subject to the performance of both products. We show that if the probability...

This paper revisits the debate about the appropriate differential equation that governs the evolution of knowledge in models of endogenous growth. We argue that the assessment of the appropriateness of an equation of motion should not only be based on its implications for the future, but that it...

This paper revisits the debate about the appropriate differential equation that governs the evolution of knowledge in models of endogenous growth. We argue that the assessment of the appropriateness of an equation of motion should not only be based on its implications for the future, but that it...