This dissertation is made of three distinct chapters that empirically investigate financial innovation in different fields: household finance, public finance and financial institutions. The first chapter presents a work joint with Claire Célérier,analyzing the growing complexity of retail structured products, and how bank use complexity to mitigate competitive pressure.The second chapter, joint with Christophe Pérignon, studies how local governments strategically use toxic loans according to their political incentives. The third chapter explores the effects of exercising contingent capital, and how these instruments can contribute to solving the bank leverage dilemna.