Essays on vertical mergers, advertising, and competitive entry

This dissertation consists of three independent essays. We briefly introduce these essays in chapter 1 and leave a comprehensive introduction to each essay. Chapter 2 considers a vertically separated industry where production takes time and vertical mergers shorten production time. We investigate the impact of vertical mergers on the downstream firms' ability to collude and show that vertical mergers facilitate downstream collusion. Chapter 3 provides a theoretical foundation for a puzzling empirical observation that advertising follows an inverted U shape for some new products. Chapter 4 analyzes an incumbent's response to a competitive entry. We show that if the quality of the entrant is uncertain, the incumbent can "jam" the quality signalling of the entrant. Finally, chapter 5 summarizes main conclusions of three essays.