Book excerpt: The aim of my thesis is to investigate the effect of competition on financial intermediaries in light of the conflicts of interest and perverse incentive structures that exist in the financial system. The first chapter of my thesis, Credit Rating and Competition investigates the conflict of interest arising from the issuer pay compensation model of the credit rating industry using a theoretical model of competitive interaction. Rating agencies balance the benefits of maintaining reputation (to increase profits in the future) and inflating ratings today (to increase current profits). Our results suggest that, unless new entrants have a higher reputation vis-a-vis incumbents, rating agencies are more likely to inflate ratings under competition relative to monopoly, resulting in lower expected welfare. The second chapter, Market Frictions, Interbank Linkages and Excessive Interconnections, studies banks' decision to form financial interconnections. I develop a model of financial contagion that explicitly takes into account the possibility of crisis. This allows me to model the network formation decision as optimising behaviour of competitive banks. I show that regulatory intervention in the form of deposit insurance and more implicit too big to fail type perceptions of government guarantees creates a wedge between social and private optimality. In the presence of these implicit and explicit guarantees, competitive banks find it optimal to form socially suboptimal interconnections in equilibrium. The final chapter, Competition, Premature Trading and Excess Volatility, attempts to explain the empirically observed excess asset price volatility as a consequence of competitive interaction between market participants. Our model shows that in the presence of competitive pressures, market participants find it optimal to act prematurely on unverified, noisy information. This premature reaction leads to lower total profits, excess market volatility and spike in volatility at the closing time of the market.