The purpose of this project is to discuss the astronomical development from the heliocentric theory to the geocentric theory. The main goal is to eliminate the common misconception that the Copernican system simply entails a change in the frame of reference from the Ptolemaic system. In particular, we will show how the Copernican system allows us to determine the size of the Universe (in terms ...

We study a setting in which firms produce items whose quality is ex-ante unobservable, but learned by customers over time. Firms take customer learning into account when making production decisions. We focus on the effect that the review process has on product quality. Specifically, we compare equilibrium quality levels in the setting described above to the quality that would be produced if cus...