Essays In Macroeconomics And Financial Markets

This thesis is composed of three independent articles. The first two chapters are on the topic of asset bubbles. In the first chapter, I study the interactions between rational asset bubbles and product market competition. I build a theoretical model where I show that asset bubbles, by providing a production or entry subsidy, may have a pro-competitive effect and force firms to expand and cut profit margins. I use the model to interpret the evidence of two famous bubble episodes: the British railway mania of the 1840s and the dotcom bubble of the 1990s. In the second chapter, I provide a comprehensive characterization of non-fundamental stock price fluctuations at the industry level. Among other things, I show that overvaluation shocks tend to be more important in industries with higher profit margins or higher R&D intensity. I also document that, in periods of high over-valuation, stock market entrants tend to be less productive. In the third and last chapter I characterize the evolution of business dynamism in Spain between 1995 and 2007. Consistent with the evidence for other developed countries, I document a significant decline in the Spanish firm entry and exit rates over this period. I also show that, when compared to incumbents of the same industry, young firms have become relatively more productive. I build a model featuring firm dynamics and financial frictions to show how a decline in interest rates can explain these trends.