Bruno Biais

COMPETING MECHANISMS IN A COMMON VALUE ENVIRONMENT

Consider strategic risk-neutral traders competing in schedules to supply liquidity to a risk-averse agent who is privately informed about the value of the asset and his hedging needs. Imperfect competition in this common value environment is analyzed as a multi-principal game in which liquidity suppliers offer trading mechanisms in a decentralized way. Each liquidity supplier behaves as a monopolist facing a residual demand curve resulting from the maximizing behavior of the informed agent and the trading mechanisms offered by his competitors. There exists a unique equilibrium in convex schedules. It is symmetric and differentiable and exhibits typical features of market-power: Equilibrium trading volume is lower than ex ante efficiency would require. Liquidity suppliers charge positive mark-ups and make positive expected profits, but these profits decrease with the number of competitors. In the limit, as this number goes to infinity, ask (resp. bid) prices converge towards the upper (resp. lower) tail expectations obtained in Glosten (1994) and expected profits are zero.

Price Discovery and Learning during the Preopening Period in the Paris Bourse

Before the opening of the Paris Bourse, traders place orders and indicative prices are set. This offers a laboratory to study empirically the tâtonnement process through which markets discover equilibrium prices. Since preopening orders can be revised or canceled before the opening, indicative prices could be noise. We test this against the hypothesis that preopening prices reflect learning. Early in the preopening the noise hypothesis is not rejected. As the opening gets closer, the informational content and efficiency of prices increase and the learning hypothesis is not rejected. We also propose a GMM‐based estimate of the speed of learning.

Large risks, limited liability, and dynamic moral hazard

We study a continuous-time principal-agent model in which a risk-neutral agent with limited liability must exert unobservable effort to reduce the likelihood of large but relatively infrequent losses. Firm size can be decreased at no cost or increased subject to adjustment costs. In the optimal contract, investment takes place only if a long enough period of time elapses with no losses occurring. Then, if good performance continues, the agent is paid. As soon as a loss occurs, payments to the agent are suspended, and so is investment if further losses occur. Accumulated bad performance leads to downsizing. We derive explicit formulae for the dynamics of firm size and its asymptotic growth rate, and we provide conditions under which firm size eventually goes to zero or grows without bounds.

An optimal IPO mechanism

We analyse the optimal Initial Public Offering (IPO) mechanism in a multidimensional adverse selection setting where institutional investors have private information about the market valuation of the shares, the intermediary has private information about the demand, and the institutional investors and intermediary collude. Theorem 1 states that uniform pricing is optimal (all agents pay the same price) and characterizes the IPO price in terms of conditional expectations. Theorem 2 states that the optimal mechanism can be implemented by a non-linear price schedule decreasing in the quantity allocated to retail investors. This is similar to IPO procedures used in the U.K. and France. Relying on French IPO data we perform a GMM structural estimation and test of the model. The price schedule is estimated and the conditions characterizing the optimal mechanism are not rejected.

Optimal Leverage and Aggregate Investment

We analyze the optimal financing of investment projects when managers must exert unobservable effort and can also switch to less profitable riskier ventures. Optimal financial contracts can be implemented by a combination of debt and equity when the risk-shifting problem is the most severe while stock options are also needed when the effort problem is the most severe. Worsening of the moral hazard problems leads to decreases in investment and output at the macroeconomic level. Moreover, aggregate leverage decreases with the risk-shifting problem and increases with the effort problem. Copyright The American Finance Association 1999.

Hindsight Bias, Risk Perception, and Investment Performance

Once they have observed information, hindsight-biased agents fail to remember how ignorant they were initially; “they knew it all along.” We formulate a theoretical model of this bias, providing a foundation for empirical measures and implying that hindsight-biased agents learning about volatility will underestimate it. In an experiment involving 66 students from Mannheim University, we find that hindsight bias reduces volatility estimates. In another experiment, involving 85 investment bankers in London and Frankfurt, we find that more biased agents have lower performance. These findings are robust to differences in location, information, overconfidence, and experience.

Floors, dealer markets and limit order markets

In dealer markets, liquidity suppliers have entire flexibility to bargain on the price with their customers. In limit order markets, they are restricted to convex schedules: they cannot sell the first share at a higher price than the second. Floor traders simply respond to the liquidity demand conveyed by brokers by crying out one price. In floor markets risk-sharing is inefficient and spreads are large. In dealer markets, risk-sharing can be efficient, but spreads tend to be large. In limit order markets, the unique equilibrium entails efficient risk-sharing and competitive spreads. Hence there is a non-monotonic relation between the efficiency of the market and the extent to which the offers of the liquidity suppliers are restricted.

Credit, Wages and Bankruptcy Laws

We study the impact of different bankruptcy laws in general equilibrium, taking into account the interactions between the credit and labour markets, as well as wealth heterogeneity. Soft bankruptcy laws often preclude liquidation, to avoid ex-post inefficiencies. This worsens credit rationing, depresses investment and reduces aggregate leverage. Yet, tough laws do not necessarily maximize social welfare or emerge from the legislative process. Relatively rich agents can invest irrespective of the law. They favour soft laws that exclude poorer entrepreneurs from the market and thus reduce labour demand and wages. This raises the pledgeable income of the entrepreneurs who still can raise funds, and thus lowers their liquidation rates and the associated inefficiencies. Hence, a soft law can maximize social welfare.

Imperfect Competition in Financial Markets: An Empirical Study of Island and Nasdaq

The competition between Island and Nasdaq at the beginning of the century offers a natural laboratory to study competition between and within trading platforms and its consequences for liquidity supply. Our empirical strategy takes advantage of the difference between the pricing grids used on Island and Nasdaq, as well as of the decline in the Nasdaq tick. Using the finer grid prevailing on their market, Island limit order traders undercut Nasdaq quotes, much more than they undercut one another. The drop in the Nasdaq tick size triggered a drop in Island spreads, despite the Island tick already being very thin before Nasdaq decimalization. We also estimate a structural model of liquidity supply and find that Island limit order traders earned rents before Nasdaq decimalization. Our results suggest that perfect competition cannot be taken for granted, even on transparent open limit order books with a very thin pricing grid.

Short Sales Constraints, Liquidity and Price Discovery: an Empirical Analysis on the Paris Bourse

In the Paris Bourse some stocks are traded on a spot basis, while others are traded on a monthly settlement basis. The latter are likely to be less subject to leverage and short sales constraints. We empirically analyze the consequences of this difference on the order flow and the return process. Consistent with the theoretical analysis of Diamond and Verrechia (1987), we find that market sell orders are less frequent on the spot market than on the monthly settlement market (although not very significantly) and that the spot market reflects good news (significantly) faster than bad news.