Financial Engineering

We investigate the welfare implications of operating alternative market structures known as electronic crossing networks or "dark pools" alongside traditional "lit" markets. We study equilibria of a market where intrinsic traders and speculators, endowed with heterogeneous fine-grained information, endogenously choose between dark and lit venues. We establish that while the dark pool attracts relatively uninformed investors, the orders therein experience adverse selection.

We model an electronic limit order book as a multi-class queueing system under fluid dynamics, and formulate and solve a problem of limit and market order placement to optimally buy a block of shares over a short, predetermined time horizon. Using the structure of the optimal execution policy, we identify microstructure variables that affect trading costs over short time horizons and propose a resulting microstructure-based model of market impact costs.

Contingent capital (CC), which intends to internalize the costs of too-big-to-fail in the capital structure of large banks, has been under intense debate by policy makers and academics. We show that CC with a market trigger, in which direct stake-holders are unable to choose optimal conversion policies, does not lead to a unique competitive equilibrium, unless value transfer at conversion is not expected ex-ante. The "no value transfer" restriction precludes penalizing bank managers for taking excessive risk.

We consider a broad class of dynamic portfolio optimization problems that allow for complex models of return predictability, transaction costs, trading constraints, and risk considerations. Determining an optimal policy in this general setting is almost always intractable. We propose a class of linear rebalancing rules and describe an efficient computational procedure to optimize with this class. We illustrate this method in the context of portfolio execution and show that it achieves near optimal performance.

Effective monitoring by equity blockholders is important for good corporate governance. A prominent theoretical literature argues that the threat of block sale ("exit") can be an effective governance mechanism. Many blockholders are money managers. We show that, when money managers compete for investor capital, the threat of exit loses credibility, weakening its governance role. Money managers with more skin in the game will govern more successfully using exit. Allowing funds to engage in activist measures ("voice") does not alter our qualitative results.

We develop a dynamic contingent-claim framework to model S. Myers's idea that a firm is a collection of growth options and assets in place. The firm's composition between assets in place and growth options evolves endogenously with its investment opportunity set and its financing of growth options, as well as its dynamic leverage and default decisions. The firm trades off tax benefits with the potential financial distress and endogenous debt-overhang costs over its life cycle.

We develop a structural model for the analysis of systemic risk in financial markets based on asset price contagion. Specifically, we describe a mechanism of contagion where exogenous random shocks to individual agents in an economy force portfolio rebalancing and endogenously impact asset prices. This, in turn, creates a chain reaction as downstream agents trade in reaction to price changes.

Recent years have seen extensive investigation of the information aggregation properties of markets. However, relatively little is known about conditions under which a market will aggregate the private information of rational risk averse traders who optimize their portfolios over time; in particular, what features of a market encourage traders to ultimately reveal their private information through trades? We consider a market model involving finitely many informed risk-averse traders interacting with a market maker.

We analyze a model of optimal capital structure and liquidity choice based on a dynamic tradeoff theory for financially constrained firms. In addition to the classical tradeoff between the expected tax advantages of debt and bankruptcy costs, we introduce a cost of external financing for the firm, which generates a precautionary demand for liquidity and an optimal liquidity management policy for the firm.