Essays on asymmetric information and trading constraints

This thesis contains three essays exploring the asset pricing implications of asymmetric information and trading constraints. Chapter 1 studies how short-sale constraints affect the informational efficiency of market prices and the link between prices and economic activity. I show that under short-sale constraints security prices contain less information. However, short-sale constraints increase the informativeness of prices to some agents who learn about the quality of an investment opportunity from market prices and have additional private information. This, in turn, can lead to higher allocative efficiency in the real economy. My result thus implies that the decrease in average informativeness due to short-sale constraints can be more than compensated by an increase in informativeness to some agents. In Chapter 2, I develop an equilibrium model of strategic arbitrage under wealth constraints. Arbitrageurs optimally invest into a fundamentally riskless arbitrage opportunity, but if their capital does not fully cover losses, they are forced to close their positions. Strategic arbitrageurs with price impact take this constraint into account and try to induce the fire sales of others by manipulating prices. I show that if traders have similar proportions of their capital invested in the arbitrage opportunity, they behave cooperatively. However, if the proportions are very different, the arbitrageur who is less invested predates on the other. The presence of other traders thus creates predatory risk, and arbitrageurs might be reluctant to take large positions in the arbitrage opportunity in the first place, leading to an initially slow convergence of prices. Chapter 3 (joint with Dömötör Pálvölgyi) studies the uniqueness of equilibrium in a textbook noisy rational expectations economy model a la Grossman and Stiglitz (1980). We provide a very simple proof to show that the unique linear equilibrium of their model is the unique equilibrium when allowing for any continuous price function, linear or not. We also provide an algorithm to create a (non-continuous) equilibrium price that is different from the Grossman-Stiglitz price

Short sale constraints, divergence of opinion and asset values: evidence from the laboratory

The overvaluation hypothesis (Miller 1977) predicts that a) stocks are overvalued in the presence of short selling restrictions and that b) the overvaluation increases in the degree of divergence of opinion. We design an experiment that allows us to test these predictions in the laboratory. The results indicate that prices are higher with short selling constraints, but the overvaluation does not increase in the degree of divergence of opinion. We further find that trading volume is lower and bid-ask spreads are higher when short sale restrictions are imposed. JEL Classification: C92, G14 Keywords: Overvaluation Hypothesis , Short Selling Constraints , Divergence of Opinio

Price dynamics, informational efficiency and wealth distribution in continuous double auction markets

This paper studies the properties of the continuous double auction trading mechanishm using an artificial market populated by heterogeneous computational agents. In particular, we investigate how changes in the population of traders and in market microstructure characteristics affect price dynamics, information dissemination and distribution of wealth across agents. In our computer simulated market only a small fraction of the population observe the risky asset's fundamental value with noise, while the rest of agents try to forecast the asset's price from past transaction data. In contrast to other artificial markets, we assume that the risky asset pays no dividend, so agents cannot learn from past transaction prices and subsequent dividend payments. We find that private information can effectively disseminate in the market unless market regulation prevents informed investors from short selling or borrowing the asset, and these investors do not constitute a critical mass. In such case, not only are markets less efficient informationally, but may even experience crashes and bubbles. Finally, increased informational efficiency has a negative impact on informed agents' trading profits and a positive impact on artificial intelligent agents' profits

The Relevance of Short Sales to the Maltese Stock Market

The paper discusses the possible effects of short sales on the operation of a very small stock market such as the Maltese one. After studying the basic mechanics of short selling procedures, the paper reviews the salient literature with particular reference to how short sales may enhance informational efficiency and their relationship with liquidity. The paper proceeds by examining these relationships in the context of the Maltese securities market. The study reveals that short sales may be desirable on the Maltese stock market for enhancing price efficiency and liquidity, yet a more formal framework for conducting such transactions is required. In addition, short positions may be particularly risky in the context of the Maltese stock market, due to low liquidity levels.Short Sales, Malta Stock Exchange, Liquidity

Short sale constraints, divergence of opinion and asset value: Evidence from the laboratory

The overvaluation hypothesis (Miller 1977) predicts that a) stocks are overvalued in the presence of short selling restrictions and that b) the overvaluation increases in the degree of divergence of opinion. We design an experiment that allows us to test these predictions in the laboratory. The results indicate that prices are higher with short selling constraints, but the overvaluation does not increase in the degree of divergence of opinion. We further find that trading volume is lower and bid-ask spreads are higher when short sale restrictions are imposed. --overvaluation hypothesis,short selling constraints,divergence of opinion

Market Bubbles and Wasteful Avoidance: Tax and Regulatory Constraints on Short Sales

Although short sales make an important contribution to financial markets, this transaction faces legal constraints that do not govern long positions. In evaluating these constraints, other commentators, who are virtually all economists, have not focused rigorously enough on the precise contours of current law. Some short sale constraints are mischaracterized, while others are omitted entirely. Likewise, the existing literature neglects many strategies in which well advised investors circumvent these constraints; this avoidance may reduce the impact of short sale constraints on market prices, but may contribute to social waste in other ways. To fill these gaps in the literature, this paper offers a careful look at current law and draws three conclusions. First, short sales play a valuable role in the financial markets; while there may be plausible reasons to regulate short sales-- most notably, concerns about market manipulation and panics -- current law is very poorly tailored to these goals. Second, investor self-help can ease some of the harm from this poor tailoring, but at a cost. Third, relatively straightforward reforms can eliminate the need for self-help while accommodating legitimate regulatory goals. In making these points, we focus primarily on a burden that other commentators have neglected: profits from short sales generally are ineligible for the reduced tax rate on long-term capital gains, even if the short sale is in place for more than one year.Short sales, Momentum traders, Value investors

Manipulations and repeated games in future markets

This chapter analyzes the possibility of manipulation in futures markets, concentrating on the effects that manipulation may have on their informational efficiency . We use the concept of manipulation as it arises in the study of noncooperative games with imperfect information . The problem can be summarized as follows : disclosure that is, (less anonymity) may prevent manipulation and therefore improve the informational efficiency of the market . On the other hand, disclosure (less anonymity) may restrict entry, and therefore produce an efficiency loss. There is, in this sense, a tradeoff between informational efficiency and free entry.futures; efficiency; futures markets; games; game theory; manipulation; imperfect information; disclosure; repeated games; one-shot game

PRICE DYNAMICS, INFORMATIONAL EFFICIENCY AND WEALTH DISTRIBUTION IN CONTINUOUS DOUBLE AUCTION MARKETS

This paper studies the properties of the continuous double auction trading mechanishm using an artificial market populated by heterogeneous computational agents. In particular, we investigate how changes in the population of traders and in market microstructure characteristics affect price dynamics, information dissemination and distribution of wealth across agents. In our computer simulated market only a small fraction of the population observe the risky asset’s fundamental value with noise, while the rest of agents try to forecast the asset’s price from past transaction data. In contrast to other artificial markets, we assume that the risky asset pays no dividend, so agents cannot learn from past transaction prices and subsequent dividend payments. We find that private information can effectively disseminate in the market unless market regulation prevents informed investors from short selling or borrowing the asset, and these investors do not constitute a critical mass. In such case, not only are markets less efficient informationally, but may even experience crashes and bubbles. Finally, increased informational efficiency has a negative impact on informed agents’ trading profits and a positive impact on artificial intelligent agents’ profits.

"The Finance Constraint Theory of Money: A Progress Report"

The theory of money that emerged from the Keynesian Revolution is coming increasingly into question, and a variety of new theories are being put forward as alternatives. The most promising is one I will call the finance constraint theory. This paper is a progress report on its development. It is particularly fitting that this progress report appear in afestschrift for S.C. Tsiang, as he has been one of the most cogent critics of the conventional theory and a major architect of the finance constraint alternative. The issues a theory of money should address may be divided into three broad areas: (1) What is money and how is it special (2) What is the connection between money and its various "prices" (the general price level, interest rates, and exchange rates)? (3) What is the role of money in economic fluctuations? After some introductory material, each of these areas will be taken up in turn.